Canosa is two-player abstract strategy board game based on sirens from Greek mythology. In the mythos, sirens were often depicted as either mermaids or winged bird-like humans whose hypnotic voices caused sailors to crash their ships and drown.
In the game, each player is a siren competing to capture as many shipwrecked sailors in the open water as then can and return them to their respective island.
The rings are the resource in the game that act as the siren's voice. Use them to capture your opponents' sailors, then call them to your island. The first player to bring four sailors to their island wins.