The boat starts moored at TENDER FRONT, a forward anchorage in the South China Sea. Slip the mooring and the patrol clock runs. Every departure is a new sortie.

Hostile merchants are generated at PALAWAN STAGING. They weigh anchor, run the convoy lane, offload, and turn around. The anchorage keeps launching replacements, faster as the war heats up. Friendly convoys cycle between TENDER FRONT and TENDER LAGONA. They are marked blue. Sinking one costs 2000 points.

Rearm at any friendly base: come inside the 1.2 km tender ring, all stop, off the bottom. The home waters are a sanctuary. Hostiles will not fight you there. The win is the tonnage quota, ten enemy merchants. Lose the hull and the patrol is over. A strategic missile strike scores, and the war continues.

The loadout is sized for a long tonnage war: 24 homing torpedoes, 10 supercavitating, 10 STORM, 8 over-the-horizon cruise missiles, 4 tactical nuclear cruise missiles, and 4 submarine-launched ballistic missiles. A visit to the tender fills all of it.

V cycles the centre view. The side panels stay up. Passive sonar is a bearing-by-time waterfall: a merchant paints a thin shaft-rate line, an escort paints a broad cavitation blob, and your own speed washes the scope with self-noise. The C-scope, A-scope, and LOFAR are the other three tubes a watchstander would actually have.

The periscope is a thermal picture of the real coastline, useful only at 11 metres or shallower. Ships are heat, hottest at the funnel, and land hides whatever is behind it. The RF scope is the other side of radiating: your own transmission, their fire-control radar, and the exposure bar that fills until they have a fix.

The bottom scan reads the same seafloor the boat can grind on. A 5-arc-minute chart cannot see a ledge, so procedural relief fills that band. The warning, the view, and the boat's own climb-off-the-floor behaviour all use that one floor.

Positions are longitude and latitude. Speeds and weapon ranges stay in metres. The coastline is the Natural Earth 1:10 m land layer, baked into the binary, so the game never phones home for a map. Land slides the hull. A hard hit on the bottom destroys it. A gentle touch grinds until you rise. Weapons that run onto land dud. The ballistic missile is the exception: it has to cross the coast.

The camera zooms from a few kilometres across to the whole Earth. The route view is the same chart. Click to lay waypoints, including a charted base, and P hands the telegraph to the pilot. That pilot is separate from the combat autopilot that drives the title-screen demo.

Your own sonar is short-legged. Friendly drone and AWACS nodes watch the surface inside a fixed coverage ring. With the RF uplink up — mast buoy, towed array, or the boat near the surface — every ship in that ring arrives as a hard track. Go deep and dark and the live feed stops. Tracks you already paid for coast on as dead-reckoned estimates, tagged EST, and fade over about 80 seconds.

The KRAIT is the strike arm of that picture. Designate a contact the network holds and fire from any depth. The missile drinks the network on its own datalink, so you can cut your uplink after launch. The tactical nuclear round uses the same gate and a wide burst. Stay outside it.