To set up, each player has three little fish in the first line of an empty sea tile, with the board being comprised of four boards pushed together to form a square. To become bigger, fish must eat plankton. When you move to a space where there is a fish of the same size or smaller than you, you capture it. Small fish are fast but vulnerable; they can capture small fish but can be captured by any fish, and they are the only ones that can go through shipwrecks. Medium fish can capture small and medium fish, and they can't go through shipwrecks. Big fish can capture fish of any size, and they can't go through shipwrecks. Race to eat five fish first!