The rules of Underwater Hockey are fairly simple. Basically it is a non contact sport, a player cannot interfere with another player with their free hand. There is no off side rule howevre shepherding and obstruction is not allowed. The puck must not rest on the glove or be carried on top of the bat or stopped deliberately by anything other than the bat.
Any infringement of the rules is judged by the 2 in water Referees who signal to the out of water referre to sound the buzzer to stop play. Depending on the seriousness of the foul the Referees can award a free puck giving a 3m advantage to the disadvantaged team or can eject players for 1or 2 minutes or for the reminder of the game. If a foul has stopped a certain goal with 3m of the goal then the Referees can award a penalty 2 on 1, or just award a penalty goal.