BAFFLES

North Atlantic, 1984

A Victor-class submarine has slipped through the GIUK gap. You are the quiet boat on its tail. Build a firing-quality target-motion solution from passive sonar bearings, hold it for ten seconds, and leave without ever being heard.

BAFFLES is a tactical stealth simulation about the geometry of underwater sound. The contact is never simply painted onto your map: 720 live track hypotheses form a particle-filter solution. Successive bearings constrain them, but only an own-ship course change creates enough parallax to separate target range from target speed.

At the conn

• W / S — engine telegraph
• A / D — hold rudder
• R / F — rise or dive in 25 m steps
• Space — record a passive bearing
• Q — transmit active sonar for precise range (and announce yourself)
• H / P — controls and pause

The acoustic model combines spherical spreading, absorption, ambient and self-noise, array signal-to-noise ratio, a thermocline shadow penalty, depth-dependent cavitation and reciprocal counter-detection. Five knots is a hole in the water; flank speed is a confession. Active sonar is survivable once and reckless twice.

A competent passive trail takes about a minute. The five-minute watch leaves room to recover from a bad leg. Keyboard and touch controls have full parity, all sound is synthesized with WebAudio, and the entire game ships as one self-contained HTML file.