• Deploy a sub (free starter modules are auto-issued).
• Hunt enemy subs and/or mine materials.
• Extract to bank everything: cargo → warehouse, score/kills + cargo → RP, modules → back to inventory.
• Die and your sub drops a wreck holding its modules and cargo — recoverable by lifter for a few minutes, then gone.

• Tap/click anywhere on the map (with your sub selected) — the boat turns to face that point and holds the new heading.
• For fine control, use the rudder in Submarine Controls — set a rudder angle or nudge it a few degrees at a time.
• The boat turns at its tuned turn rate, and speed costs turn rate — at full speed you turn about half as fast. Slow down to come about quickly.
• The HEADING readout shows current → target while the turn completes.

• Type a target depth and Set — the boat planes to it and holds. Pitch buttons give manual control.
• SNORKEL takes you to 10 m; BLOW is the emergency surface (limited charge).

• Throttle drains battery; the generator recharges it.
• Classic diesel only charges at snorkel depth (≤15 m). The self-circulating diesel charges at any depth. The nuclear reactor needs enriched uranium and careful rod/turbine management.
• Running the diesel above 60% power damages the engine.
• Watch the 🔋 battery alarm: at 0 battery the prop stops. Cut throttle and let the generator catch up.

• Passive sonar is silent and free — bearing-only contacts ("bearing 140°, range medium").
• Active ping gives range + position but reveals you to everyone who hears it.
• Thermal mode spots hot reactors and running diesels — counters acoustic stealth.
• You are louder when fast, shallow, or snorkeling. Deep + slow = quiet.

• Torpedo range is battery-limited. A straight (non-homing) run goes ~4× farther than a homing one — fire on a bearing, then flip homing on when it's close.
• Explosive: proximity fuze + blast radius; damage falls off with distance.
• EMP (up to 25 m/s): drains target battery and can SCRAM nuclear reactors. Restarting takes 60+ s, and a reactor left down too long dies permanently. Reactors tuned for fast charging couple harder with the pulse — a 1.5× charger loses 1.5× the battery per hit.
• Detection drone: a remote sonar picket you can steer.
• Decoy: fakes your noise signature for ~3 minutes.
• Reloading tubes costs battery and takes time.

• Call a Miner (Materials panel) targeting iron, copper, or uranium nodes. It mines, returns, and docks cargo into your sub.
• Cargo in your sub is not yours yet — extract to bank it.
• Refine at base (Craft panel, only while not deployed): 3 iron → 1 steel · 5 copper → 1 electronics · 4 uranium → 1 enriched uranium (reactor fuel).
• Refinery sliders cap at what your stock can produce.

• Call Extraction — a waypoint appears 2–4 km away.
• The lifter takes several minutes to arrive (you'll get the 🚁 alert when called and when it's exposed).
• Hold inside the 500 m zone at snorkel depth (~2 min boarding) to complete it.
• Payout: RP from kills (50 each) + score + cargo — iron/copper 1 RP, steel/electronics 2 RP, uranium 4 RP per unit. Modules return to inventory.

• Death drops a wreck at your position holding your modules + cargo.
• Send a lifter to salvage it — a wreck a lifter is heading for won't decay; unclaimed wrecks vanish (modules lost) after ~5 min.
• Salvaged modules return to their original owner's inventory; minerals go to the salvager.

• RP unlocks recipes in the 🔬 Research Store; crafting consumes warehouse materials (qty slider caps at what you can afford).
• Each crafted module is a distinct instance with its tuning frozen in — spawning binds one; losing the sub without salvage loses it.
• Tuning is point-buy: pushing a stat above stock costs points; tuning below stock refunds points to spend elsewhere.

• 🔔 Alerts & Sound (menu): sound effects, spoken voice callouts (pick your voice), volume, and OS notifications.
• Notifications reach you even when the tab is backgrounded or closed (allow them when prompted; on phones, add the site to your home screen on iOS).
• The Alert Log keeps a timestamped history of everything that fired this session.

Every action in the UI is backed by a REST API — you can drive your subs entirely from scripts or bots.

• Docs: open /docs in your browser for interactive Swagger UI. Click Authorize and paste your API key to unlock the full spec.
• Key: your API key is shown after login/signup. Add it to every request as Authorization: Bearer <key>.
• Example:
  curl -H "Authorization: Bearer <key>" /world/snapshot
• The spec groups routes by tag: sub (movement, depth, throttle), torpedo (launch, steer, speed), reactor, sonar, loadout, extraction, logistics, and realtime (SSE snapshot stream).