Stolen from the San Diego Club Website:
 UNDERWATER HOCKEY, getting started...
Underwater hockey is a "breath-hold" sport. Players wear a mask, snorkel, fins along with a 12 inch hockey stick and padded glove. It is a "real" sport, with regional, national, and international tournaments. In these tournaments there are refs, timers and athletes with serious intent, but during "friendly" games and practice sessions, it is more like any other sport where people just get together and play without the formality and time structure of a tournament.

There are quite a few athletes playing underwater hockey. There are a lot more "wish I was an athlete" players. The water is an equalizer so newer players, men and women, young or old can play in the same game with the "jocks". Virtually all of the clubs/teams are coed. Underwater hockey is a great cardiovascular workout and a lot of fun. Some clubs are more competition oriented and some are more "'recreation" oriented. Even in a competition oriented club a "non-athlete" can still have a good time and stay in tip top shape for diving and other sports.

STRATEGY:
The primary objective of underwater hockey is to push, pass, and shoot the puck into the opponents' goal as often as possible while preventing the other team from scoring in your goal. A good way to start is to have three players designated as "forwards" and three as "backs". As in basketball, a goalkeeper is not necessary. The puck is pushed along the pool bottom with the side of the stick and a pass is accomplished by a combined motion of pushing, swinging the lower arm from the elbow, and flicking the stick with the wrist. A good pass for beginners is 4 to 6 feet. World class players shoot 10 to 15 feet.

Time on the bottom is not long but is repetitive. Timing and pacing can do more than one long burnout on the bottom which leaves you on the surface for longer periods of recovery.

A successful offensive play is to dive down, receive a pass from a teammate and complete a pass to another teammate. Passing advances the puck faster than swimming or pushing it. A successful defensive play is to steal the puck from an opponent and complete a pass to a teammate. It is very important to remember that you may take the puck away from an opponent, but you may not take an opponent away from the puck.

BASIC RULES:
Six players (more or less for informal recreational play) on each team. One team has black sticks, the other team has white. Teams line up at opposite ends of playing area with the puck centered between them on the pool bottom. At an agreed on signal "White-Black ready, Go!", team members race to the puck and try to control it with their sticks, passing to team members or taking it away from opponents. A score or goal is made when the puck passes completely through or into the designated goal area.

After a goal, teams line up and restart (within 30 sec. in tournaments). Nothing should contact the puck except the playing area of the stick. No body to body contact (unless your stick is on the puck). Only one hand is allowed on the stick (use hand protection) and the free hand may only be used for swimming, to protect yourself from flying fins, or to push off the bottom. It is illegal to obstruct an opponent in any way while not in possession of the puck.