Plot coordinates and mark all hidden vessels on the opponent's grid sheet before they mark yours.

• Fleet: Flagship (size 5), Cruiser (4), Frigate (3), Sub-vessel (3), Scout (2), Lifeboat (1).
• Placement: Vessels must be drawn horizontally or vertically. They cannot overlap, extend past the sheet edge, or touch adjacent vessels (including diagonally).
• Marking: Alternate turns. A marked "Hit" turns red, a "Miss" turns white on the grid sheet.
• Sinking: When all grid cells of a vessel are marked, the vessel is sunk.
• Salvo Mode: Players get coordinates to mark equal to their number of surviving vessels.
• Hidden Hitters: Hit indicators are marked, but the specific vessel type is not revealed until it is completely sunk.