From: Lineage 7421 of the Wave Riders
Type: Tidefield Detection Apparatus / Oceanic Ley Scanner
Form & Function:
A brace-mounted coral-steel instrument that clasps along the upper foreleg or harness anchor. It resembles a spiral conch fused with bronze veinwork, connected by three tide-filament rings that rotate when activated. When submerged or near powerful spray (like ship bow wake or waterfall mist), the coil emits soft pulses of hydromantic resonance that return pressure echoes, allowing the bearer to detect anomalies in current flow, hidden ley breaches, submerged tunnels, or movement from large aquatic beasts approaching through low-visibility waters.
Sensory Output:
The device doesn’t display information visually; instead, it translates the returning resonance into subtle vibrations against the bearer’s limb, allowing instinctive interpretation based on pressure rhythm—perfectly aligned with Apsaran amphibious sensory instincts.
Cultural Note:
These coils are issued only to lineage guardians or sea-route surveyors and must be ritually rinsed in Tidetower basins before each patrol. The act is known as “teaching the coil the taste of home.”
Lore
First prototyped along the storm-throats beneath Tidehaven after a series of vanishing skiffs, the coil marries spiral conch geometry with bronze veinwork tuned to tidal harmonics. Deep-Silver surveyors discovered that Apsaran foreleg nerves interpret rhythmic pressure more quickly than eyes parse glyphs, so the coil speaks through touch alone. Each unit is taught a baseline in a Tidetower basin before duty—“the taste of home”—so that foreign wakes, false mouths in the reef, and ley leaks thrum as wrong notes against a remembered chord. Veteran guardians claim the best coils can feel the breath of a leviathan before its shadow rises.
Specific Slot
Apparatus slot—Brace Mount (upper foreleg or harness-anchor rail). Counts as a tool apparatus, not armor. Attunes when latched and wetted; unattunes when fully dry for a watch.
Tier One Stat Adjustments
+1 Perception (hydro-sensory only: currents, spray, wake, and vibration cues).
+1 Insight when interpreting environmental risk at sea, surf, or waterfall mist.
–1 Stealth penalty while the rings are rotating (soft chime in still air; silent in spray).
Skills Gained
Tide-Echo Parsing: You can read pulse rhythms as distance, size, and direction; advantage on checks to detect submerged passages, concealed inlets, or prow-wakes in low visibility.
Ley-Draft Sketching: With chalk or Aque-Script, you can mark quick “ley arrows” from memory after a scan; allies gain a small bonus to navigation checks that follow your marks that same watch.
Wake-Discrimination Drill: Identify beast-wake versus hull-wake by cadence; advantage to avoid ambush lanes or choose safer approach vectors.
Passive Magics
Currentsense Haptics: While the coil is damp, micro-pulses map a short envelope around you. You feel pressure taps that correspond to obstacles, tunnels, or large movers within that envelope.
Spray Lock Stability: In bow spray or waterfall mist, the rotating rings automatically phase-cancel deck vibration, reducing false positives from your own motion.
Home-Basin Bias: After a ritual rinse, echoes matching your home waters produce a calm, even cadence; anything non-native to that baseline hums off-beat for immediate attention.
Echo-Curtain Filter: The conch cavity dampens reverberation off kelp and rigging, cutting “clutter” in crowded water by a modest degree.
Activatable Magics
Pulse Ping (at-will; breath-count cooldown): Emit a narrow hydromantic ping. You receive a three-tap pattern that conveys range band and bearing to the nearest significant anomaly (ley breach, tunnel mouth, large creature) within a short scan arc.
Longcast Sweep (2/long watch): Rings widen and spin faster; extend range to a moderate distance in a 90-degree sector. Grants a sizable bonus to the next navigation or scouting check based on the result; imposes brief arm numbness (no second activation this round).
Needle-Focus (1/scene): Tighten the beam to thread a specific channel or rib between coral heads. You gain precision on depth and aperture width sufficient to choose which swimmer can fit without scraping gear.
Beast-Wake Gate (1/scene, reactive): On sensing a rapid, converging wake, the coil issues a hard triple-press; you may immediately dodge, brake, or side-slip with a small bonus, even in murk, as you’re guided to the thinnest pressure lane.
Ley-Breach Tell (1/scene): Harmonizes against your home-basin chord to “sing out” a nearby leak or thin spot; you feel heat-cold pulses indicating severity tiers. Overuse within the same watch risks echo fatigue.
Handling, Limits, and Safety
Overwhelm: Continuous Longcast or repeated Pings in choppy crosscurrents can flood sensation; suffer a brief disorientation penalty to perception until you take a steadying breath-count.
Dry Quiet: In arid, still air the coil is mostly mute; Passive Magics require moisture. Activations work at reduced efficacy until re-wetted.
Misdirection: False keels, decoy bubble curtains, or echo-shield creatures create doubled rhythms; on a poor read the bearing inverts for a heartbeat before self-correction.
Cooldown Discipline: Each activation requires a breath-count reset; forcing back-to-back uses risks ring stall (next activation at disadvantage and audible chime revealed).
Tags
Tidefield Scanner, Conch-Resonance, Brace-Mounted Apparatus, Hydro-Echo Mapping, Ley Leak Detection, Wake Discrimination, Basin-Tuned, Spray-Optimized, Nonvisual Readout, Apsaran Survey Gear, Reefward Patrol Standard, Pulse Ping Cadence, Longcast Sector Sweep, Needle-Focus Beam, Beast-Wake Early Warning, Ley-Breach Alarm, Spray-Phase Noise Cancel, Basin-Memory Calibration
Where Hydro-Pulse Survey Coil 8832 of the Reefward Path is acquired in Saṃsāra
- Grand Tidetower Instrumentarium, Tidehaven (issue-only, consecrated stock)
How: Assigned to lineage guardians and sea-route surveyors after a basin-memory calibration and oath record. Civilian sale is not permitted; temporary mission loans require a royal or Wavekeeper writ.
Cost: Sacred stewardship fee of 8 Gold (or 16 Electrum) for issuance, refundable on return in working order; re-calibration free for active patrols. - Coralia Major Reef-Cartography Vault (research variant)
How: Academic lease to certified cartographers, ley-engineers, or guild apprentices under mentor bond; includes lab access for ley-draft logging.
Cost: 5 Gold per month lease; purchase price 40 Gold with guild charter and publication clause; 1 Silver per session for basin-rinse consumables. - Port Aqua-Vel Tidewrights’ Guildhall (commercial survey pattern)
How: Merchant fleets and harbor authorities procure coils for mapping channels, wreck-runs, and traffic lanes. Comes with spray-phase noise-cancel tuning.
Cost: 28 Gold per unit; 2 Gold for shipboard brace kit; 5 Silver per Longcast retune. - Iron-Tide City Brass & Veinworks (industrial make, non-consecrated)
How: Rugged, factory-balanced models for dredgers, pipe-layers, and river engineers. Less sensitive to ley nuance, more shock-tolerant.
Cost: 18 Gold; bulk orders (6+) at 15 Gold each; 1 Gold for ring-bearing replacements. - Mistfall Sanctuary Echo-Cell (bespoke artisan coils)
How: Hand-tuned by Deep-Silver artisans to the bearer’s foreleg nerve profile; includes private training in tide-echo parsing. Waiting lists are common.
Cost: 1 Platinum (10 Gold) commission retainer; 32 Gold on delivery; first two re-tunes free within a year. - Aeridor Perch Sky-Survey Annex (aerial mist-grade)
How: Calibrated for cliff fogs, waterfall plumes, and zeppelin bow-spray. Popular with griffon rangers patrolling mist-cliffs.
Cost: 30 Gold; 3 Silver per high-altitude pressure membrane swap. - Pearlwater Reefwalkers’ Exchange (refurbished, deconsecrated)
How: Retired patrol coils appear after formal de-oathing and basin cleanse; buyers may pay for re-consecration by a licensed Wavekeeper.
Cost: 12 Gold refurbished; +2 Gold for re-consecration; +5 Silver for fresh basin-memory imprint. - Tidehaven Dock-Wardens’ Cage (alarm-time requisition)
How: Short-term issue during harbor emergencies to any sworn defender; must be returned for rinse and report the same watch.
Cost: Deposit 6 Gold per coil; 1 Silver per hour usage fee (waived if action confirmed). - River-Delta Caravan Chapels (frontier stock)
How: Traveling Wavekeeper-smiths carry two or three coils for remote outposts where charts are poor. Paperwork light; rite mandatory.
Cost: 24 Gold fixed; barter accepted at caravan’s discretion (e.g., a week of armed escort). - Blackrope Underdecks, Pearlwater (illicit salvage)
How: Salvaged coils from wrecks or theft; often still “remember” a prior basin and can give false bearings until cleansed. Purchase risks sanction.
Cost: 4–10 Gold depending on condition; 1 Gold for a gray-market purge rite (quality not guaranteed).
Etiquette, rites, and operating costs
• Basin-Memory Calibration: Required before first patrol and after 7 days dry; reputable shops include one free calibration. Typical fee 5 Silver otherwise.
• Ring Service: Rotating tide-rings need replacement every 50 scans in sandy surf; legit counters charge 8 Silver per set, Underdecks half that with higher stall risk.
• Oath Ledgering: Lineage guardians sign the Reefward path ledger with each purchase/lease; falsifying lineage invites confiscation and fines up to 20 Gold.
• Trial Demos: Guildhalls will run a three-ping dock demo at no charge; additional demos 2 Silver each.
• Resale Rules: Consecrated coils are not legally sold—only transferred under writ or de-oathed first. De-oath rite fee 1 Gold.
Use the Hydro-Pulse Survey Coil as a touch-language that writes the battlefield on your foreleg. It does not “see”; it tells you where pressure breaks, wakes converge, and tunnels breathe. Below are roleplay cues for defense and offense in varied environments, describing what you feel, how you act, and how scenes change when the rotating rings hum.
Open sea, rolling swell
Defense: keep the coil damp in bow spray. A steady, even thrum means clean water; an off-beat double-tap from starboard foreshadows a fast hull-wake or charging beast. Call Beast-Wake Gate the instant the triple-press hits; side-slip along the thinnest pressure lane without needing visuals. Longcast Sweep when visibility collapses; describe arm-numbness and a wider cone of awareness—“the water ahead feels hollow on the left,” guiding you around riptides and ambush angles.
Offense: ping to find the lee behind a predator’s flank—the echo comes back thin where the body shields current. Needle-Focus through that gap and drive the pursuit into your allies’ arcs. If raiders mask approach with foam, the coil reads false chaff as smeared, grainy taps; chase the single crisp tap to the real skiff.
Coral shelves and reef mazes
Defense: currents braid; clutter rises. Echo-Curtain Filter trims kelp chatter so a clean two-tap reveals a tunnel mouth. Mark the rock with a quick ley arrow and lead the group through without scraping barding. When a reef-stalker circles, the cadence tightens into a drumbeat; step off the line two strides before it appears—the coil has already “heard” the turn.
Offense: funnel foes. Pulse Ping to plot two exits, then feint toward the wider pressure lane; when the pursuer commits, Needle-Focus the narrow chimney and slip through. The enemy collides with pressure they misread and stalls at the pinch where allies wait.
Kelp forests and wreck interiors
Defense: kelp knocks like rain on canvas; a beast’s wake presses in a long, smooth push. Read the difference by palm texture—staccato for fronds, velvet for muscle. Use Beast-Wake Gate reactively to brake at a cross-corridor just as a tentacle sweeps across the doorway.
Offense: “see” around corners. Longcast Sweep down a cargo passage; the return comes back as a hollow cylinder for clear space, a soft cork for a closed hatch, and a jagged cork for a barricade of bones and nets. Pick the route that lets your line emerge behind the intruder.
Harbor alleys, piers, and crowded docks
Defense: in crowd churn, deck vibration can spoof senses. Spray Lock Stability cancels your own footsteps so foreign wakes stand out. When a cloaked cutpurse darts along a pier edge, the coil registers a narrow absence where their body shunts wash from pilings; announce that lane and block without drawing steel.
Offense: expose hidden swimmers and net divers. Pulse Ping from a mooring underbridge; the echo slaps back shallow-deep-shallow—there’s a diver dragging a line. Call the direction so wardens can hook the rope instead of the person. For de-escalation, use Ley-Breach Tell at low power near a sabotaged sluice; the heat-cold pulses “out” the tampering without accusing a bystander.
Mist cliffs, waterfalls, and levitating platforms
Defense: perpetual spray is your ally. The rings sing softly; everything slows into readable cadence. Set Needle-Focus to thread wind-carved holes behind the falls; guide a line past a hidden shelf without anyone stepping into a void. On sky bridges, a sudden triple-press with lateral drift warns of a griffon stoop; you drop and slide into the laminar seam where the wake cannot follow.
Offense: create safe lanes. Longcast along a cliff face to map crosswinds; call out a numbered stride pattern—“three fast, one hold”—and your team moves as if they can see the air. If saboteurs ride updrafts, Pulse Ping the column; the strong, straight return betrays their exact perch.
River deltas and swamps
Defense: muddied water hums low; a crocodilian glide reads as a leveled, creeping pressure. Tap once to warn, twice to freeze; allies keep feet planted until the wake passes or rises. If poachers stretch a near-invisible line, the coil returns a taut “string” you feel across the wrist; you stop the lead before anyone clotheslines themselves.
Offense: shepherd threats. Ping to locate the warm outlet where predators prefer to surface; you steer the party onto firm sand bars while a net team readies at the only viable approach.
Blackout storms and night actions
Defense: the coil replaces sight. Describe the world in taps—“two long at twelve, hollow on nine, broken glass at three”—and move with conviction. Beast-Wake Gate buys a heartbeat to avoid a blindside ram on a heaving deck.
Offense: choreograph catches. Call Longcast once to map three approaching wakes; assign lanes aloud by cadence—“first drum to me, the hiss to stern, the stumble to port.” Your crew acts on rhythm rather than sight and meets boarders exactly where water says they must appear.
Convoys and escort duty
Defense: hold Scan discipline. One Pulse Ping every few breaths to avoid overwhelm; home-basin bias keeps honest wakes calm and highlights foreign hulls. If a decoy bubble screen approaches, the coil reports double rhythms—announce the “echo within an echo” and hold fire until the true mass registers.
Offense: counter-flank. Longcast along the convoy’s shadow side; a bowed return indicates an eddy lane raiders love. Reposition before they arrive, turning their favorite route into a kill box.
Anti-ambush at tide gates and passes
Defense: stand at the throat of a channel; the coil memorizes the gate’s pulse after a rinse. Any foreign breach—swimmer in the undertow, hauled net across the mouth—sounds as a syncopated hitch. Signal early so the first move is yours.
Offense: fix and flank without sightlines. Needle-Focus to plot the shallower of two rips; send the fast mover through while you maintain Longcast on the deeper rip to pin down the ambusher’s only safe retreat.
Urban investigations and sabotage hunts
Defense: in dry interiors the coil is near silent; damp a cloth and sling it over the conch to wake minimal function. You’ll still feel the faintest draft under a door or the hollow of a hidden cistern.
Offense: prove tampering. Ley-Breach Tell near a smugglers’ valve lights your nerves with a hot-cold ladder proportional to the leak. You don’t accuse; you invite a warden to lay hands and feel it too.
Behemoth and leviathan encounters
Defense: a leviathan breath reads like the sea reversing. The baseline hum collapses, then returns with weight. Beast-Wake Gate is your only truthful early-warning—describe the foreleg jolt and order a hard turn before any silhouette breaks the surface.
Offense: map the safe shadow. Longcast around the mass; you will feel a vast “silence” where your pulses vanish into living depth. Lead the line along that edge, avoiding fluke wash that would flip a ship.
Team choreography and call-outs
• Speak in cadences, not compass: “Two-tap left, long-push ahead,” so allies of any culture understand.
• Mark with quick ley arrows in chalk where the coil told you to pass; your memory sketch gives latecomers an actual path.
• When rings stall from overuse, say it plainly in character—“My ear is full”—and hand the lead to the next scout until your breath-count reset.
Common pitfalls and how to play them
Overwhelm: too many Pings in chop? Roleplay vertigo—shake the foreleg, take one long breath, resume with a single Needle-Focus.
Dry quiet: inside warehouses, accept the coil’s humility; wet it or use it as a stethoscope on barrels to feel liquid slosh for hidden caches.
Misdirection: echo-shields create mirrored bearings; commit to the first correction you feel, then verify with a second Ping rather than chasing phantom doubles.
Table flavor lines to sell the feel
“The coil thumps twice—someone’s wake is wearing ours like a cloak.”
“The wall ahead feels hollow; step where the water sounds thin.”
“Triple-press—down now. Let the beast pass where we were.”
Play the coil as a living metronome of the sea. Defense means refusing to be surprised; offense means putting foes where the water already intends them to go.
Perception of Activation:
User’s Perspective:
A cool, tightening band settles around the foreleg as the tide-filament rings begin a soft, fingertip-felt spin. Pressure taps bloom along the brace like raindrops spelling a word—three light beats forward (open water), a longer, weightier thrum to starboard (moving mass), a hollow flutter below (cavity or tunnel). Bow spray changes taste on the tongue, faintly metallic, as the coil “learns” the local water; heartbeat steadies to match the device’s tempo. Deck vibration fades to a hush, leaving only the clean push-pull of currents against skin. When a wake converges, the brace delivers a sudden triple-press—urgent, precise—guiding a side-step before sight catches up. Longcast feels like pins-and-needles creeping up the limb, followed by a widening bubble of certainty about where water flows easily and where it feels thick, slow, or “wrong.”
Extra-Sensory Perceptions:
Currents translate into textures: silk-smooth lanes (safe pass), corded rope-pulls (strong wakes), felted drag (kelp or nets), glassy slicks (bubble screens, echo-shields). Ley seepage announces itself as a cool-then-hot pulse ladder climbing the foreleg, with irregular rungs for unstable breaches. Beast-wakes register as velvet pressure arcs crossing at living rhythm—breath-length pauses between pushes—distinct from the mechanical, metronomic chug of hulls. Elevation shifts are audible through bone: waterfall mist “rings” high and thin; deep-channel drop-offs thud low and slow, like distant drums. After basin rinse, familiar waters hum in a gentle, even chord; anything foreign strikes a discordant off-beat that prickles the wrist.
Observer’s Perspective:
Fine mist halos the conch spiral while the bronze veinwork flashes with fleeting, pearly sheen. The three tide-rings rotate out of sync, then harmonize, shedding hairline rivulets that bead and vanish. The bearer’s foreleg makes micro-corrections—half-steps and hip-shifts—as if following invisible markers on the deck. In heavy spray, a faint chiming whisper briefly rises and then dampens, coinciding with a clean, confident change in the bearer’s stance or path. During a sudden convergence, the user moves early—ducking a sweeping boom, skirting a slick, or stopping at a threshold—moments before the hazard visibly manifests.
Positives:
• Nonvisual mapping in blackout, silt, or storm; converts hidden flow and mass into intuitive pressure language.
• Early-warning triple-press for rushing wakes enables preemptive dodges and lane choices without sightlines.
• Spray-phase noise canceling filters out deck tremor and self-movement, reducing false positives in rough seas.
• Basin-memory bias highlights non-native wakes and clandestine tunnels as immediate rhythm mismatches.
• Needle-Focus delivers precise aperture and depth reads, allowing safe passage through tight coral or wreck ribs.
Negatives:
• Dry, still air renders signals faint or silent; forced activations feel dull and can chime audibly in quiet rooms.
• Crosscurrent clutter and bubble screens may cause double-images—a momentary inverted bearing before self-correction.
• Overuse (rapid Longcasts or repeated Pings) leads to echo fatigue—foreleg numbness and brief disorientation.
• Strong mechanical vibration from nearby engines or pumps can mask subtle beast-wakes unless re-tuned.
• If not basin-rinsed for many days, the coil’s “home chord” drifts, increasing false alarms and misreads until recalibrated.
Recipe Title: Constructing the Hydro-Pulse Survey Coil 8832 of the Reefward Path
Materials Needed
• Conch-grade spiral shell (sound, uncracked; inner spiral length equal to bearer’s foreleg from knee to fetlock)
• Coral-steel billet (for frame ribs and bracing brackets), refined in seawater-tempered bloom
• Lumin-bronze veinwork (thin capillaries, 0.5–1.0 mm internal bore), pre-annealed for cold bends
• Three tide-filament rings (matched set), composed of lumin-bronze rims with pearl-ash bearings and reed-thin magnetite vanes
• Aque-Script filament resin (bioluminescent polyp gel, pearl ash, dawn tidewater) for micro-channel lining
• Damp-cord packing (kelp fiber treated with antifouling salt) for vibration isolation within the conch cavity
• Brace-mount yoke and rail (hardened coral-steel), sized for foreleg or harness anchor
• Sealant wax (luminwax) for waterfast sealing of joins and micro-channels
• Basin-water from a consecrated Tidetower (moving; not stagnant) for imprint and calibration
• Fine silver thread for node lashes and ring retainers
• Optional: basin-memory token (strand of lineage hair, reef-pebble, or oath-bead) to bind home-chord bias
Tools Required
• Steam forge with directional vanes (wet heat; no dry furnace)
• Conch-lathe and soft-jaw shell clamps (low-pressure)
• Capillary bender and micro-mandrels for veinwork routing
• Pearl-ash brazing lamp (low-flame, steam-shrouded)
• Aque-scribing stylus and capillary brush for micro-glyph channels
• Bearing arbor and ring-balancing cradle (free-spin test stand)
• Vibration table with spray manifold (to simulate bow wake)
• Pressure bath (shallow tank with adjustable laminar and crossflow)
• Brace fitting jig for foreleg or harness-rail sizing
• Calibration trough (moving basin-water) and echo board (for tap pattern practice)
Skill Requirements
• Conch acoustics: shaping cavities to target resonance without craze lines
• Wet brazing: joining lumin-bronze to coral-steel with steam-shrouded, low-oxidation technique
• Micro-fluid routing: bending veinwork without kinking or altering bore diameter
• Aque-Script micro-engraving: shallow glyphs that carry filament resin without choking channels
• Echo parsing: ability to read and grade tap patterns during tests
• Rite observance: basin-memory imprint, oath ledgering, and home-chord bias establishment
Crafting Steps
- Conch selection and seasoning
Select a conch with continuous, unflaked inner spiral. Soak in moving seawater for one watch, then sunshade-dry until surface matte. Reject any shell that sings with a rattling tone when lightly tapped. - Cavity shaping
Mount the conch in soft-jaw clamps. On the conch-lathe, thin the inner walls by a whisper, preserving the natural spiral. The goal is a clear, bell-like tone when blown across the mouth. Line interior bearing seats with damp-cord packing to damp high-frequency chatter. - Frame rib and yoke fabrication
Forge the coral-steel ribs to cradle the conch’s exterior and accept the brace-mount yoke. Wet-bend the ribs to match shell curvature; never force dry bends. Drill anti-torque holes for silver-thread lashes. Prepare the foreleg or harness-rail yoke in the fitting jig to the wearer’s measure. - Veinwork routing
Map three primary lumin-bronze capillaries along the conch’s exterior, following the spiral—one intake, one emitter, one recirculation line. Cold-bend with micro-mandrels to avoid bore collapse. Dry-fit with reed-thin magnetite vanes at junctions to assist ring coupling. - Wet brazing and sealing
Steam-shroud all joints. Pearl-ash braze veinwork to frame pads and conch saddles with the smallest possible fillets. Wick luminwax sealant into every seam. Inspect bores with a fine wire—no snagging permitted. - Tide-filament ring assembly and balance
Seat the three rings on pearl-ash bearings around the conch’s midline: forward, mid, and aft nodes, 120 degrees offset. Spin each on the balancing cradle; a correct ring free-spins for a nine-count with no lateral wander. Correct wobble by micro-trimming a vane or shifting a single bearing grain. - Aque-Script channeling
With the scribing stylus, cut shallow channels from the forward ring to the emitter capillary, then to the aft ring. Add three micro-glyph clusters along the bearer-facing side: pulse, gate, and home. Paint channels with filament resin using the capillary brush; resin should wick to a pearly line, not pool. - Brace mounting and isolation
Lash the frame ribs to the conch with silver thread through pre-drilled holes. Seat the assembly in the coral-steel yoke. Insert isolation shims of damp-cord where shell meets metal. Tighten until no rattle remains but the shell can “breathe” under hand pressure. - Pressure bath tuning
Place the coil in the pressure bath. Run laminar flow across the intake and watch ring behavior. Adjust vane angle until ring rotation begins at a light flow and synchronizes under bow-wake simulation. The emitter should produce a faint, regular tap against the echo board. - Spray-phase noise cancel calibration
Move the assembly to the vibration table and engage spray manifold. Tune the mid ring and recirculation line to phase-cancel deck tremor. Success is a clean tap pattern on the echo board while the table vibrates. - Home-chord bias imprint
Rinse the coil in moving basin-water at a Tidetower. If using a lineage token, rest it on the brace while you speak the patrol name. The home glyph should glow faintly; the tap cadence should flatten into an even, calm rhythm. Record the imprint in the ledger. - Field cadence drills
Strap to the bearer’s foreleg or harness anchor. In bow spray, perform Pulse Ping and Longcast trials. The user should feel three distinct cadences: short taps (obstacle), long thrum (moving mass), hollow flutter (void or tunnel). If patterns blur, re-open veinwork bends by a fraction and repeat.
Quality Checks and Failure Signs
• Ring drift or stall: bearing grit contamination; rinse in basin-water, re-seat pearl-ash grains, re-balance vanes.
• Harsh metallic chime in spray: isolation shims too tight or missing; add damp-cord packing.
• Overly hot or numb foreleg after Longcast: emitter capillary restriction; clear bore and reduce vane angle one degree.
• No tap in bow spray: intake misaligned; rotate intake capillary along the spiral to a higher-pressure zone.
• False double bearings: echo-shield artifacts; verify veinwork symmetry and re-tune recirculation timing.
Calibration and Consecration Rites
• Pre-patrol rinse: a brief moving-basin immersion “teaches the coil the taste of home.” Skip this and expect drift, false alarms, and muddied cadence.
• Seven-day dry reset: if the coil has remained dry a full week, perform a full home-chord re-imprint before use.
• De-oath and re-oath: for transfer between lineages, cleanse in basin-water with neutral chant, then re-imprint under new oath; record both rites.
Maintenance
• After-action flush: run moving seawater through intake and emitter for a ten-count.
• Bearing care: replace pearl-ash bearings every fifty scans in sandy surf; earlier if rings squeal.
• Seal renewal: re-wick luminwax at brazed joints each month or after any heavy impact.
• Storage: keep lightly damp in a sealed sling; do not sun-bake or leave in stagnant water.
Variants (optional)
• Cliff-fog pattern: widen vane pitch by one degree for thin spray environments; improves sensitivity in waterfalls and levitating platforms.
• Industrial dredge pattern: heavier ribs, thicker capillaries; sacrifices fine ley sensitivity for shock resistance.
• Deep-scout pattern: elongated conch cavity and extended emitter line; increases range, adds arm fatigue—train accordingly.
Safety Notes
• Do not dry-fire Longcast in still, arid air; vane snap and audible chime risk detection.
• Limit consecutive Pings; echo fatigue presents as foreleg pins-and-needles and degraded discrimination.
• Never bypass isolation shims; shell fracture begins as hairline craze invisible to the eye but audible as a brittle over-tone.
When constructed and tuned by these steps, the Hydro-Pulse Survey Coil speaks through touch with clean, reliable cadence, mapping wakes, voids, and breaches without light—and without hesitation.
Conch That Heard River Inside Sea
They say in parchments bent by wet and years, copied from a time when words were still learning how to be straight, that there was once a shell which did not only sing when you put it to the ear, but listened when the world put itself to the shell. The first telling names it Coil-of-Listening, but the second telling writes it as Spiral-of-Three-Rings, and a later scribe with a tired hand calls it Only-Conch-That-Does-Not-Lie. These are the same thing, argued sideways.
In those days the sea near Tidehaven forgot its manners. Skiffs went out with bread and line and came back as empty names. Nets fetched only water. Pilings hummed with a sound like a throat trying to remember a song. People said the reef had grown new mouths, or the wind had stolen the road from the water, or that old storms were hiding under new waves. No one agreed, because agreeing is difficult when the ocean is being different.
There was an artisan whose name is variously written as Maen, Mehan, or Maan-of-Hollow-Sound. This person—some papers say woman, some say man, one says “the one with shoulders like a careful ox”—took the lost skiffs into the lap and listened to their wood. A broken boat will tell you what touched it, if you ask with a good silence. The boats spoke in knocks and thuds and drips, and the artisan nodded as if that were a language that did not need letters.
“Your eyes are loud,” said Maen to the wardens, in a sentence that looks like a mistake but is correct. “Shut them. The sea is saying ‘here’ with its hands.” But closing eyes did not make the world polite. So Maen went to the markets and found a conch with a spiral that seemed to wish to go on forever. The shell had no crack and made a tone like a single hair being pulled across silver. Maen cradled it and said, “You are a mouth that will be an ear.”
There was bronze made thin like veins, and coral-steel bent like a promise that will mostly be kept. There were three little rings set around the spiral, and each ring had many small intentions sticking out, which scholars later called vanes. The conch was held by ribs of metal, like a cage that was not a prison. When it was built, it was not yet awake. It was brought to a basin in a Tidetower. Water was moving in the bowl, because water that sits still forgets its name. Maen dipped the conch and said the short oath that means “remember home.” The basin hummed, the conch did nothing, and the wardens shifted their weight in the way that means “we were hoping for a miracle, and now we have to use patience.”
After a time the first ring moved, not in a circle but in a thinking. The second ring answered. The third ring was shy. The conch shivered like a sleeping calf and then held still. “It knows the taste of here,” said Maen. “Now we will ask what does not taste like here.”
They strapped the thing to an Apsaran foreleg—the good place between bone and breath—and walked into the tide where the water lays its hand upon your knee. The ring made a small tapping on the skin, foolish at first, then less foolish, then a word without letters. The wardens said they felt the shape of the pier as a flat drum, the nearby boat as a slow push, and an emptiness under the surface like a missing tooth in the mouth of the harbor. They all looked at the missing tooth and found a tunnel mouth worn by currents that nobody had asked permission. “That is where the skiffs were swallowed,” said someone with useful fear.
Maen said, “You can see with eyes later. Walk where the taps say.” So they went: three short taps meant “forward,” a long thrum meant “thing moving,” and a hollow flutter meant “hole, careful.” It was like stepping along invisible stones that other feet had put there long ago. They set a line across the mouth and listened. The conch said, in its way, that something big was thinking about becoming present. It was not a fish and not a boat. It was a large wrong. The water made it known by pushing the wrong way.
Out of the tunnel came raiders in a skiff that had been taught how to sit on a bubble instead of on the sea. This is clever in a school way but rude in a spirit way. The skiff made no wake because it was lying. The rings did not like that lie. They scraped the foreleg with a triple-press the way a mother pinches a child away from fire: not to hurt, but to command. The warden stepped sideways into a path that existed for no one else yet. The skiff slid past where the warden had been, confusing itself. The second warden pulled the rope that had been set, and the skiff remembered that even lies have weight.
The raiders spoke through masks of oil and had hooks that had never learned kindness. The coil whispered through taps where the hooks would swing, and arms moved before thoughts had arrived. It was an odd dance. The wardens walked in confidence where they could not see, and the raiders tripped where they could not think. It ended with hands on boards and the skiff ashamed of its bubbles. The basin was brought to the pier and the conch was dipped again. The rings turned easier. A name was written down—not a human name but a promise-name: Reefward Path. The numbers were added later by careful people who like to count things, and they wrote 8832 because that was the right flavor of number.
The story has a middle where pride tries to be taller than purpose. A harbor-master whose name changes eight times in eight copies said, “If the coil hears the sea, we will teach it to shout also.” They set the rings to spin faster and hotter, and they tried to make the conch speak to rocks to move them, and sing to tides to change their mind, and argue with a leviathan’s slow breath. The conch did not shout. It rang like a spoon struck against a thin bowl. The bowl cracked inside where the eye cannot look. The coil began to make a high sound that meant “I am unhappy.” Maen lifted it away from tools and said nothing, which is a kind of warning older than words.
That night, when the moon held a wet coin between its fingers, the leviathan that is called by some Fish-of-Before-Songs and by others She-of-Deep-Doors came to the harbor mouth as a shadow that makes shadows. The coil woke with a shaking like a horse that knows thunder before thunder is audible. The rings pressed a rhythm that was not language but was more urgent than language. The wardens moved the boats and the ropes and the people without needing to decide to do it. The leviathan passed, and the water leaned after her like a child leaning after a story that is not finished.
In the morning the harbor-master apologized with fruit and silence. The coil was taken to the basin. Maen dipped it and said the short oath backwards, which sometimes is a healing. The conch forgot the night’s fear and remembered the taste of home. Shells can learn, this is known.
There were other tests. In a reef like a forgotten city, where corridors were made by old patience, the coil tapped hollow where a tunnel woke, tapped velvet where a creature breathed, tapped sand-rough where nets had been sneaked by hands that push and do not pull. The wardens used the taps to be where danger was not yet, and to leave where danger would be soon. They drew arrows in chalk that meant “here the water is kind” for those who could not wear a coil. The chalk arrows were like short prayers, and even people who did not believe in prayers put their feet on them because they worked.
In a place called Many-Falls, where water is always telling the same story but never in the same words, the coil learned to listen to mist like a harp you stand inside. Needle-fine taps became instructions: step and then wait, then step two. A griffon stooped out of cloud like a fast question, and the coil pinched a triple-press, and the warden said “down” to bones before mouth, and the air was where the claw arrived instead of the person. Later they laughed like survivors and fed the griffon a fish with apologies because he was only being himself in the wrong page of the book.
There is a chapter where a bubble screen is used by smugglers, and the coil saw double, and the warden almost walked into the wrong true, and then remembered to breathe until the rings settled to a single beat. There is a page where dredgers borrowed an industrial coil, tuned for wanting, not for nuance, and it led them through silt to a buried wreck that was tired of being underground. The coil tapped hollow, then tapped stone, then tapped greed, and the men argued, and the coil sided with the quieter one, and they brought up cargo that fed a winter. The myth says that even machines can prefer certain people. Perhaps this is unkind to machines. Perhaps it is true.
There is the tale of the child called Peh or Beh or “the short one,” who put the conch to the cheek and said, “It is humming like a cat that is thinking.” The elders were about to scold for the touching, but Maen said, “Let the child be taught by the wrong way once.” The coil tapped a joke into the small arm—three quick taps at the elbow, which means “mind the turning,” and the child stopped short of a slick stair. “You see?” said Maen. “The tool chooses the language the hand understands.”
The end, which is not the end, is written as a procession. The coil was given a number and a path-name and a ledger page. More coils were made, some excellent, some adequate, a few made by people who liked to make but did not like to listen. Those few ringed too loud or too proud, and their owners learned the price of showing off. The good coils were rinsed in basins before patrols. They were taught the taste of home so that foreign things would be noisy to them. When kept dry too long they forgot and became nervous and rang wrong. Then they were carried to the basin again and forgiven.
Once, a coil refused a new owner. The rings would not turn. The taps were stingy and cruel. The warden said the coil was broken. Maen, who by then was an old page with a soft voice, took the coil to the basin, washed it as if washing a foal, and spoke the oath for the new name three times: forward, caution, return. The coil shivered and then agreed. “It is not broken,” said Maen. “It was insulted by being asked to work without being invited.”
In the final margin—the one that crumbles if you breathe too hard—there is a prickly sentence: “A thing made to hear must be taught to listen.” And below it, darker, perhaps written by a hand that had lost too much: “And those who wear the listening must hear also.”
The coil became standard for Reefward Path watchers. It sat on forelegs the way a reminder sits on a memory—light, persistent, kind when you do right, severe when you try to be clever in a foolish way. On nights when sight was only myth, the forelegs of guardians spoke to them with taps, and they walked lanes that did not exist for eyes. On days when raiders wrapped lies around boats, the coils unwrapped them with small fingers of pressure. When leviathans passed, the coils made bowing a reflex instead of a decision, which is the difference between being in a story and being a warning.
Some copies add a funeral: when Maen went to the deeper lesson, the coil that is called First was unstrapped and washed until the metal remembered rain. It was placed on the Tidetower’s stone and the basin’s lip, where water is about to become journey, and people came to lay fingers on it and then on their own wrists, to remind their hands how to be ears.
There were later coils that spun faster and farther, and some that tried to talk to the sea with arguments instead of questions. They did not last. The ones that kept the old gentle beat lasted. They are still in the ledgers, and sometimes the ledgers come open by themselves, which is superstition that has the shape of truth.
Moral of the story: Teach your tools the taste of home, and let them teach you how the world speaks back; listen first, move next, and you will arrive where seeing has not yet caught up.
Suggested conversions to other systems:
CALL OF CTHULHU (latest edition)
Item: Hydro-Pulse Survey Coil 8832 of the Reefward Path
Type: Tidefield detection apparatus; worn brace on foreleg/arm or harness
Skills Affected: Navigate (Sea), Listen, Spot Hidden, Track, Pilot (Boat), Science (Oceanography) at Keeper’s discretion
Baseline: While damp or in spray/mist/open water, the bearer gains +10% to Navigate (Sea) and +10% to one of: Listen or Spot Hidden (choose each scene), when used to read wakes/currents rather than sight alone. In dry, still air no bonus applies.
Pulse Ping (no cost; 1/round max): Make a Navigate (Sea) or Listen roll to “ping.” On success, Keeper reveals nearest significant anomaly in a narrow arc (direction and approximate distance band). Extreme success also distinguishes living wake vs hull wake. Failure creates clutter: next coil roll this scene is at –10%.
Longcast Sweep (2/scene): Full action; Listen or Navigate (Sea) with bonus die in heavy spray/over water. On success, gain advantage (+10% or a bonus die, Keeper’s call) on the next allied sea/navigation test and learn two features (e.g., tunnel mouth and large mover). On fumble, suffer echo fatigue (–10% to coil tests until one full turn of rest).
Needle-Focus (1/scene): Listen test; on success, learn aperture width/depth sufficient to choose who/what fits safely. Grants bonus die to one immediate test to pass that feature without mishap.
Beast-Wake Gate (reaction; 2/scene): When an unseen wake converges, make a Dodge or Pilot (Boat) test with a bonus die. On success, preempt the hazard and re-position advantageously; on extreme success the threat overshoots.
Ley-Breach Tell (1/scene): Occult or Science (Physics/Oceanography) test; on success, the coil grades a nearby ley leak (minor/moderate/major). On failure, false positive; on fumble, temporary tinnitus-like numbness (–20% to Listen for 1D6 minutes).
Drawbacks: Dry Quiet (no bonuses off moisture), Crosscurrent Clutter (Keeper may impose –10% in chaotic surf), Ring Chime (on fumbles, a faint chime can betray position). Sanity: 0/1 when first comprehending a massive leviathan by pressure alone. Rarity: Restricted temple instrument.
BLADES IN THE DARK
Item: Hydro-Pulse Survey Coil 8832 (Fine Survey Gear)
Load: 1 (counts as Fine Tool; requires moisture/spray to shine)
Effect: While in mist/rain/spray/over water, you have increased effect when you Survey or Study by “reading pressure,” and you may resist environmental consequences from unseen currents/wakes with +1d.
Pulse Ping (free, once per action): On a Survey/Study, also create the temporary trait “Pressure Map (2 ticks).” Spend 1 tick to gain potency on a single navigation/approach; spend both to avoid an unseen hazard without a roll.
Longcast Sweep (2 stress): Widen the scan; gain potency and great effect to map a sector (clocks: fill 2 ticks on “Safe Route” or “Hidden Channel”). Consequence on 4/5: echo fatigue (–1d to further coil uses until you Take a Breath).
Needle-Focus (1 stress): Thread a tight pass; treat a risky traverse as controlled and gain +1d to the maneuver.
Beast-Wake Gate (reaction, 1 stress): When ambushed by an unseen mover, step into the “thin lane”: avoid the immediate consequence or convert it to a lesser one.
Ley-Breach Tell (flashback 0–1 stress): Reveal you sang the basin-memory; gain potency to detect sabotage/ley leaks and +1d to Command/Persuade when directing crews based on your map.
Complications: Dry Quiet (reduced effect off water), Ring Chime (on a critical consequence the gear draws attention), Overwhelm (push the coil twice in a scene: start a 4-tick “Echo Fatigue” clock).
DUNGEONS & DRAGONS (latest core)
Hydro-Pulse Survey Coil 8832 of the Reefward Path
Wondrous item (brace-mounted), uncommon, requires attunement by a creature with proficiency in Perception or Vehicles (water)
Moisture-Bound Senses: While you and the coil are damp or in rain, spray, mist, or above open water, you gain a +1 bonus to Wisdom (Perception) and Wisdom (Survival) checks made to detect creatures, tunnels, or hazards by current/wake, and advantage on Wisdom (Perception) checks to avoid being surprised by creatures approaching through water.
Pulse Ping (At-Will). As a bonus action, you emit a narrow pulse. Until the start of your next turn, you know the direction (not location) of the nearest submerged passage, large aquatic creature, or ley anomaly within 120 feet in a 60-degree arc you choose. This sense cannot penetrate 5 feet of stone, 2 feet of metal, or 2 inches of coral-steel.
Longcast Sweep (2/Short Rest). As an action while in moisture, you expand the scan. Choose a 90-foot cone; make a DC 13 Wisdom (Survival) check. On a success, you learn the presence and rough layout of channels, voids, and large movers in that cone (DM provides simplified map cues) and gain advantage on the next check to navigate that area before your next short rest. On a failure, you suffer echo fatigue (disadvantage on the coil’s next activation this encounter).
Needle-Focus (1/Short Rest). As a bonus action, you precisely read an aperture within 60 feet; until end of turn you and one ally ignore difficult terrain from tight coral/rigging and have advantage on checks or saves to squeeze through.
Beast-Wake Gate (Reaction; 1/Short Rest). When a creature you can’t see moves within 30 feet in water and would force you to make a Dex save or would hit you with an attack, you can move up to 10 feet without provoking opportunity attacks and gain +2 AC or advantage on that save against the triggering effect.
Ley-Breach Tell (1/Long Rest). While in a Tidetower basin or coastal ley line, you can cast detect magic without components, sensing only planar/ley disturbances and water-/air-aligned effects; duration 10 minutes, concentration.
Limitations: Dry Quiet (no features function without moisture except Needle-Focus’s movement advantage), Ring Chime (when you roll a natural 1 on an activation, you emit a faint chime audible within 20 feet). Attunement ends if kept fully dry for 7 consecutive days.
KNAVE (latest edition)
Hydro-Pulse Survey Coil 8832 (Apparatus)
Carry: 1 slot (worn on forelimb or chest harness)
Requirement: Moisture (rain/spray/mist/over water) to gain full benefits
Passive: While moist, you have Advantage on Checks to detect hidden channels, large moving creatures in water, trip lines/nets, or ley leaks by reading pressure rather than sight. You cannot be surprised by creatures approaching through water unless magically hidden.
Pulse Ping: Spend a Turn to ping a narrow arc; learn the direction to the nearest tunnel, large mover, or anomaly (GM picks) within Far. On a roll of 1 on your next Check this encounter, suffer Echo Fatigue (Disadvantage on further coil uses until you Rest).
Longcast Sweep (2 uses; refresh on Rest): Spend a Turn to map a cone out to Near x3; you and allies gain Advantage on the next Navigation/Traverse through that space and avoid the first environmental danger there.
Needle-Focus (1/use per Rest): Instantly judge a tight pass; for one Turn you and one ally ignore penalties for Squeezing and treat Slippery/Cluttered footing as normal.
Beast-Wake Gate (reaction; 1/use per Rest): When an unseen threat converges in water, immediately Step (Near) into a “thin lane”; negate one attack or hazard targeting you this moment.
Ley-Breach Tell (1/use per Rest): Sense a nearby magical leak; the GM must reveal if a location is unstable or magically compromised and its rough severity.
Drawbacks: Dry Quiet (no Advantage without moisture), Ring Chime (on a Mishap, you emit a faint chime that can reveal you). Maintenance: After seven dry days, the coil loses its Home Bias until re-rinsed at a temple or moving sea.
FATE (Core/Accelerated, latest)
Item Name: Hydro-Pulse Survey Coil 8832 (Reefward Path Pattern)
Item Aspect: “Conch That Listens Where Eyes Can’t”
Permissions: Worn apparatus; needs moisture (rain, spray, mist, or over water).
Stunts/Extras:
• Vortex Sense: When rain/mist/spray is present, gain +2 to Overcome or Create an Advantage with Notice or Investigate by reading currents, wakes, or hollow spaces.
• Beast-Wake Gate: Once per scene, when an unseen threat converges, immediately negate a mild environmental consequence or step from Risky to Controlled position in fiction; take +2 to the resulting Defend/Overcome.
• Needle-Focus Mapping: Spend 1 Fate Point to declare a tight safe lane or tunnel aperture; gain a free invoke on the created Aspect “Threaded Channel.”
Drawbacks/Compels: Dry Quiet can compel the item Aspect to reduce effect or impose –2 on current-reading actions in arid, still air; Overwhelm can compel echo fatigue after back-to-back scans (–2 to further coil uses until a brief rest).
Notes: Treat the coil as a Fine Tool; invokes can justify potency against ambushes, nets, bubble screens, and silt-outs.
NUMENERA & CYPHER SYSTEM (latest)
Item Name: Hydro-Pulse Survey Coil 8832 (Artifact, Level 5)
Form: Brace-mounted conch/bronze apparatus; nonvisual hydromantic scanner.
Effect (while in moisture):
• Passive: You have an Asset on tasks to detect submerged passages, large aquatic creatures, traps/nets in water, or ley leaks via pressure reading.
• Pulse Ping (at-will): Action; learn direction and approximate range band to the nearest significant anomaly within Long range in a 60° arc.
• Longcast Sweep (2/10 minutes): Action; map a 90° sector out to Very Long. Gain an Asset on your next navigation/scouting task in that space; allies in a party check also gain +1 step if you brief them.
• Needle-Focus (1/scene): Action; precisely gauge an aperture or safe lane, granting an Asset to a single Traverse/Squeeze/Balance task for you or an ally.
• Beast-Wake Gate (reaction, 1/scene): When an unseen wake converges, move an Immediate distance into a thin lane and treat the triggering Speed defense as trained; if already trained, treat as specialized.
• Ley-Breach Tell (1/hour): Action; Intellect task (difficulty = GM-set based on site). On success, you identify nearby planar/ley instability and its severity (minor/moderate/major) within Short.
Depletion: 1 in 1d20 (on depletion, activations cease; the brace remains a quality tool granting the passive Asset only in gentle conditions).
GM Intrusions: Crosscurrent Clutter (false echo), Ring Chime (reveals position), Echo Fatigue (temporary numbness; hindered coil tasks until a recovery roll).
Costs: Optional 1 Intellect point for Longcast or Needle-Focus when used in chaotic surf to avoid fatigue.
PATHFINDER SECOND EDITION (latest)
Item Name: Hydro-Pulse Survey Coil 8832 of the Reefward Path
Item Level 6 • Price 250 gp • Rarity Uncommon
Traits: Invested, Magical, Divination, Water, Exploration • Bulk L • Usage worn on forelimb or harness
Attunement: Requires Investiture and moisture (rain, spray, mist, or over open water) to function fully.
Passive—Moisture-Bound Sense: While moist, you gain a +1 item bonus to Perception checks to Sense Direction, notice approaching aquatic creatures, detect submerged passages, nets, or trip lines by current/wake; you gain a +1 item bonus to Survival checks to Navigate waterways and a +1 circumstance bonus to initiative in aquatic or heavy-spray encounters.
Activate—Pulse Ping (single action) Frequency at-will; Requirements moist; Effect you learn the direction to the nearest significant anomaly (GM’s choice among submerged passage, large aquatic creature, or ley anomaly) within 120 feet in a 60-degree arc. This doesn’t pinpoint a square and can’t penetrate 5 feet of stone or 2 feet of metal.
Activate—Longcast Sweep (two actions) Frequency twice per hour; Requirements moist; Effect scan a 90-foot cone. Attempt a DC 20 Survival or Perception check; on success you gain a +1 status bonus to your next check to Navigate or to a Scout/Follow the Expert exploration activity in that space, and the GM provides simplified layout cues (channels, voids, movers) for 10 minutes. On a critical success, the bonus is +2. On a failure you take echo fatigue (–1 item bonus from the coil for 10 minutes).
Activate—Needle-Focus (free action) Frequency once per 10 minutes; Trigger you attempt to Squeeze, Balance, or Tumble Through within 60 feet of tight coral/rigging; Effect you gain a +1 item bonus to the triggering check and ignore the first square of difficult terrain from slick or cluttered footing until your turn ends.
Reaction—Beast-Wake Gate Frequency once per hour; Trigger an unseen aquatic creature would cause you to attempt a Reflex save or would Strike you; Effect Step up to 10 feet and gain a +1 circumstance bonus to the save or a +1 circumstance bonus to AC against the triggering Strike.
Activate—Ley-Breach Tell (three actions, concentrate) Frequency once per day; Requirements near a coastline, waterfall, or Tidetower basin; Effect as read aura but only detects planar/ley disturbances and water/air magic; duration 10 minutes.
Drawbacks: Dry Quiet (no features function without moisture except Needle-Focus’s +1 item bonus); On a critical failure using Longcast, you emit a faint chime audible within 20 feet.
Crafting: Requires expert Crafting, formula, basin-water, and Aque-Script components.
SAVAGE WORLDS ADVENTURE EDITION (latest)
Item Name: Hydro-Pulse Survey Coil 8832 (Relic; Brace-Mounted)
Requirements: Worn; moisture (rain/spray/mist/over water) to gain full benefits.
Passive: While moist, gain +1 to Notice when detecting hidden channels, nets/lines, or approaching aquatic creatures; gain +1 to Boating/Swimming to Navigate by current. You can’t be surprised by creatures approaching through water unless they have a power or Edge that negates detection.
Powers/Effects (no Power Points; Relic features):
• Pulse Ping (Action): Make a Notice roll; on success, the GM reveals the direction and range band (Close/Medium/Far) to the nearest significant anomaly in a 60° arc. Raise: also learn live vs hull wake. Failure: next coil use this scene is –1 (echo clutter).
• Longcast Sweep (Action; 2/encounter): Notice at +1; on success gain +1 to the next Boating/Survival (tracking/navigation) roll in that sector and grant allies a +1 Support bonus if you direct them. On a Critical Failure you suffer Fatigued (Minor) from echo strain until a Short Rest.
• Needle-Focus (Free, 1/encounter): Ignore Difficult Ground from slick/clutter for your movement this round and gain +1 Athletics (Agility) to Squeeze or Tumble through tight lanes.
• Beast-Wake Gate (Free, 1/encounter; Interrupt): When an unseen threat converges in water, you may immediately move 1” and gain +1 Parry or +1 to an Evasion-like Athletics/Agility roll against the trigger.
• Ley-Breach Tell (Action, 1/session): Notice or Occult at +1; on success you identify a nearby planar/ley instability and its rough severity; on a Failure you detect a false positive (GM may place a Complication).
Hindrances/Limitations: Dry Quiet (no bonuses in arid, still air), Ring Chime (on a Critical Failure the device emits a faint chime revealing position), Overwhelm (two coil actions back-to-back impose –1 to further coil uses until you spend an action to steady).
Gear Notes: Counts as a Fine Tool for navigation scenes; if kept dry for a week, benefits suspend until a brief ritual rinse or relevant downtime.
SHADOWRUN (Sixth World, latest edition)
Item: Hydro-Pulse Survey Coil 8832 (Reefward Path Pattern)
Type: Wearable Sensor (Exotic Aquatic Scanner) • Availability: 8R • Cost: ¥4,500 • Device Rating: 4 • Slots: Worn (forearm/harness)
Prereqs: Moisture field (rain/spray/mist/over open water) to operate at full effect.
Game Effects:
• Tidefield Mapping: While active in moisture, gain +2 dice to Navigation (Watercraft) and Perception tests to detect submerged passages, nets/lines, or aquatic approaches relying on current/wake rather than sight.
• Pulse Ping (Major Action; Simple to sustain): Make a Perception + Intuition test; on success the GM provides bearing and range band (Near/Far) to the nearest significant aquatic anomaly in a 60° arc. 2+ net hits distinguish living wake vs hull wake. On a glitch, create Echo Clutter (–1 die to next coil test this scene).
• Longcast Sweep (Major Action; 2/encounter): Electronics + Logic [Sensor] test opposed by environmental noise (threshold 2–4). Success grants you and your team +2 dice to the next Navigation (Watercraft) or Gunnery (called shots vs targets emerging from water) within the scanned sector and reveals two features (e.g., tunnel mouth and large mover). Critical glitch: user suffers Echo Fatigue (–2 dice to further coil uses until a Short Rest).
• Needle-Focus (Minor Action; 1/encounter): Choose a tight channel or wreck lane within Short. You and one ally gain +2 dice to Acrobatics/Gymnastics or Pilot (Watercraft) tests to pass without collision this Round; ignore difficult terrain from slick rigging/coral.
• Beast-Wake Gate (Interrupt; 1/encounter): When an unseen aquatic threat would hit or force a Defense test, move 1 meter and add +2 dice to your Defense or Pilot test against the trigger.
• Ley-Breach Tell (Major Action; 1/day): Arcana or Engineering test (threshold 3). Success grades nearby planar/ley instability (minor/moderate/major) within 20m; failure yields a false positive; critical glitch emits a faint chime (Stealth –2 dice for 1 Round).
Limitations: Dry Quiet (no bonuses off moisture; Pulse/Longcast at –2 dice), Overwhelm (back-to-back scans impose –1 cumulative dice to further coil tests this scene), Maintenance (recalibrate after 7 dry days; 1 hour, tools or temple).
STARFINDER (latest edition)
Item: Hydro-Pulse Survey Coil 8832
Level: 6 • Price: 4,600 credits • Bulk: L • Slot: Worn (arm/harness) • Category: Hybrid (analog + magical)
Traits: Analog, Hybrid, Water, Divination
Activation: Operates best in rain/spray/mist/over open water.
Benefits:
• Tidefield Mapping: While in moisture, you gain a +2 circumstance bonus to Survival checks to navigate waterways, and a +1 circumstance bonus to Perception checks to notice submerged passages, nets/lines, trip hazards, or approaching aquatic creatures by current/wake.
• Pulse Ping (action; at-will): Choose a 60-degree arc; attempt a Perception check (DC = 15 + 1/2 your level, +2 in heavy storm). On success, learn the direction and approximate distance (30/60/120 ft) to the nearest significant anomaly (GM chooses among tunnel, large aquatic creature, ley anomaly). On a critical success, you also learn if the wake is living or mechanical. On a critical failure, you suffer echo clutter (–1 circumstance penalty to further coil checks for 10 minutes).
• Longcast Sweep (move action; 2/day): Map a 90-degree sector out to 120 ft; you and allies gain a +1 circumstance bonus to the next Piloting (water) or Survival (navigate) check taken in that sector within 10 minutes, and the GM provides simplified layout cues.
• Needle-Focus (reaction; 1/hour): When you or an adjacent ally attempts to move through tight coral/rigging, grant a +2 circumstance bonus to Acrobatics or Athletics for that movement and ignore the first 5 ft of difficult terrain from slick/clutter.
• Beast-Wake Gate (reaction; 1/hour): When an unseen aquatic foe acts within 30 ft, you Step 5 ft and gain a +1 circumstance bonus to AC or Reflex against the triggering attack/effect.
• Ley-Breach Tell (10 minutes; 1/day): As detect magic but only senses planar/ley disturbances and water/air effects; range 60 ft; duration 10 minutes.
Limitations: Dry Quiet (outside moisture, only Needle-Focus functions and all coil checks take a –1 penalty), Ring Chime (on a natural 1 with Longcast or Pulse, you emit a faint chime audible within 20 ft).
TRAVELLER (Mongoose 2e, latest)
Item: Hydro-Pulse Survey Coil 8832
TL: 9 • Mass: 0.7 kg • Cost: Cr3,500 • Traits: Wearable, Aquatic Sensor
Operating Conditions: Requires moisture (spray/mist/over water) for full effect.
Rules:
• Tidefield Mapping: While in moisture, gain DM+1 on Recon checks to detect submerged passages, nets/lines, or approaching aquatic creatures by current/wake; gain DM+1 on Navigation for waterways and pilotage in surf.
• Pulse Ping (Significant Action): Recon or Navigation check 8+. Success reveals bearing and range band to the nearest significant anomaly in a 60° arc; Effect 2+ distinguishes living vs hull wake. Failure imposes –1 DM to the next coil check this encounter (echo clutter).
• Longcast Sweep (Significant Action; 2 per watch): Electronics (Sensors) or Recon 8+. Success grants DM+1 to the next Navigation/Pilot (Small Craft—water) check for your party in that sector and provides simple layout cues; Effect 4+ grants DM+2 instead. Mishap: user suffers Echo Fatigue (–1 DM to further coil uses until a brief rest).
• Needle-Focus (Free; 1 per encounter): Choose a tight channel within Short. You and one ally gain DM+1 to Athletics (Dex) or Pilot checks to traverse without collision this Round; ignore one step of difficult ground from slick debris.
• Beast-Wake Gate (Reaction; 1 per encounter): When an unseen aquatic threat triggers a Defense/Pilot test, move 1 metre and gain DM+1 to that test.
• Ley-Breach Tell (1/day; 1 minute): Science (Physical Sciences) or Psionics (Awareness, at Referee’s option) 8+. Success grades nearby planar/ley instability (minor/moderate/major) within Short; failure produces a false read.
Limitations: Dry Quiet (no bonuses; coil tests at –1 DM), Maintenance (after 7 dry days, recalibration required at a temple or lab: 1 hour, Cr50 consumables).
WARHAMMER
Warhammer Fantasy Roleplay (latest edition)
Item: Hydro-Pulse Survey Coil 8832 (Reefward Pattern)
Rarity: Rare • Encumbrance: Negligible • Type: Worn Apparatus (Arm/Harness)
Use Conditions: Functions fully in rain/spray/mist/over open water.
Effects:
• Tide Sense: While in moisture, gain +10 to Perception or Navigation tests to read currents/wakes for hidden channels, nets/lines, or approaching aquatic foes; gain +10 Initiative in aquatic or heavy-spray encounters.
• Pulse Ping (Action): Perception Test; success reveals direction and approximate distance band to the nearest significant aquatic anomaly in a 60° arc; +SL 2 distinguishes living vs hull wake. Failure: next coil test –10 (echo clutter).
• Longcast Sweep (Action; 2/session): Perception (or Trade: Boatman) at +10; on success, you and allies gain +10 to the next appropriate Navigation/Boatman test in that mapped sector and receive simplified layout cues. Critical Failure: Echo Fatigue (–10 to further coil uses until a Short Rest).
• Needle-Focus (Free; 1/Encounter): Treat one risky traverse through tight coral/rigging as Average (+20) and ignore the first step of Difficult Terrain from slick/clutter for your movement.
• Beast-Wake Gate (Reaction; 1/Encounter): When an unseen aquatic threat would strike or force a Dodge, you may move 1 yard and gain +10 to Dodge or +1 SL to oppose.
• Ley-Breach Tell (Extended; 10 minutes; 1/Day): As a specialized Magical Sense test; on success, detect planar/ley disturbances and rate severity.
Complications: Dry Quiet (no benefits without moisture), Ring Chime (on a Fumble, emit a faint chime—Stealth tests suffer –10 for 1 Round).
Warhammer 40,000 (narrative/crunch adaptation—Roleplay/Skirmish use)
Item: Hydro-Pulse Coil, Reefward-8832 Pattern
Type: Worn Auspex (Aquatic/Atmospheric Moisture Scanner) • Availability: Rare • Weight: Minimal
Rules:
• Tidefield Auspex: In humid/rain/spray zones or over bodies of water, gain +10 to Awareness or Navigate (Surface/Water) to detect submerged passages, nets/lines, or approaching swimmers; you and allies gain +1 to Initiative when an engagement occurs from water.
• Pulse Ping (Half Action): Awareness Test; success reveals bearing and approximate range to the nearest significant anomaly in a 60° arc; 2 DoS distinguishes bio-wake vs machine wake. Failure: next coil use –10.
• Longcast Sweep (Half Action; 2/Mission): Awareness +10; success grants you/allies +10 to the next Navigation/Pilot (Surface) test in the scanned sector and the GM provides simple layout cues; Critical Failure inflicts Fatigue (1) from echo strain.
• Needle-Focus (Reaction; 1/Mission): Ignore Dangerous Terrain from slick/clutter for your movement and gain +10 to Agility tests to squeeze/slip a tight lane this Round.
• Beast-Wake Gate (Reaction; 1/Mission): When attacked from concealment by an aquatic foe, move 1 metre and gain +10 to Dodge against the trigger.
• Ley-Breach Tell (Extended; 1/Mission): Tech-Use or Psyniscience; detect localized warp/ley instability near water/air interfaces (GM adjudication).
Limitations: Dry Quiet (no coil bonuses in arid, still atmospheres), Ring Chime (on a Jam/Fumble, faint chime reveals your position to nearby foes).