Captain Sonar

Form two teams and give Captains and Radio Operators matching scenario maps. Use dark sides for real time and light sides for turn-by-turn. With 2–3 players, turn-by-turn is mandatory. Four-person crews split all roles; in a three-person crew the Captain also handles First Mate, and in a two-person crew also Engineer.

The Captain secretly chooses a sea-space start. Each ordinary course moves 1 space north, south, east or west with a clear public announcement. You cannot enter islands, your previous route or your own mines. If no course is possible, you must surface immediately.

The Radio Operator plots each enemy course on a transparent sheet and slides it over the map, checking islands and route restrictions to report possible enemy positions. Real-time crews choose their own pace; turn-by-turn crews alternate movements.

After each ordinary course, the First Mate marks an empty space on any system gauge and the Engineer crosses out an available symbol in that direction’s control panel. The Captain must wait for both to finish and acknowledge before announcing another course.

A system must be fully charged and have no breakdown in its corresponding category. Each breakdown symbol covers a pair of weapon, detection or special systems. The Captain can activate any system; the First Mate may also activate sonar and drones. Clear the relevant gauge after use, and move between system activations.

Completing all four linked symbols of a central circuit repairs and clears that circuit. Crossing out every radiation symbol or every symbol in one directional control panel causes 1 damage, then clears all breakdowns. Clearing breakdowns does not heal hull damage.

A torpedo targets a space 1–4 orthogonal steps away; announce its impact and clear its gauge. Place a mine on an adjacent space outside your old route, clear its gauge, and announce its detonation separately later, never while surfaced. An impact deals 2 damage in its space, 1 in adjacent spaces including diagonals, and none farther away. Your own submarine can be hit.

A drone asks whether the enemy submarine is in a specified sector; the enemy Captain must answer truthfully. Sonar requires two different types of location information chosen from row, column and sector, exactly one true and one false. Clear the corresponding gauge after use.

Silence allows up to 4 spaces in one straight line without publicly announcing the course, still avoiding islands and your old route; signal the direction to teammates. The First Mate still marks 1 space on a chosen system gauge, and the Engineer crosses out 1 breakdown for the indicated direction. Surfacing reveals your sector and erases the old route while preserving your position and mines. In real time, the crew traces the submarine outline for enemy Engineer approval while the enemy keeps playing; in turn-by-turn, clear breakdowns and let the enemy take 3 consecutive turns.

In real time, raise a fist and call STOP before activating a system; everyone pauses for resolution. In turn-by-turn, activate at most 1 system after your team’s course. In standard play, the first submarine to accumulate 4 damage is destroyed and the other crew wins. Follow any special objectives or surfacing restrictions on the chosen map.