Underwater hockey is a team sport played on the bottom of a swimming pool, where two teams of six use short handheld sticks to push a heavy puck across the pool floor and into opposing goals. Players wear fins, masks, and snorkels, diving repeatedly to the bottom to play the puck before surfacing to breathe. Originally called “octopush,” the sport was invented by the British Navy in the 1950s to keep divers fit and improve their ability to move and work efficiently underwater. It has since grown into a competitive international sport governed by the World Underwater Federation (CMAS), with world championships held regularly across the globe.
How the Game Works
Each team fields six players at a time, with four reserves on the bench. Substitutions can happen freely at any point during play, which is critical because players are constantly cycling between the surface and the pool floor. The puck sits on the bottom of the pool, and players dive down to advance it using their sticks, flicking or pushing it along the floor toward the opposing team’s goal trough, which sits at each end of the pool.
There is no goalkeeper in the traditional sense, though one player typically fills a defensive “full back” role. The game moves in three dimensions: players jockey for position on the bottom, surface to catch their breath, then dive back into the action. This constant rotation between breathing and playing gives the sport a unique rhythm. You can’t hold your position on the bottom indefinitely, so teamwork and timing matter as much as individual skill.
Equipment Players Use
The stick is surprisingly small. It must fit inside a box measuring 350mm long, 100mm wide, and 50mm deep, roughly the size of a small baguette. Sticks are made from wood, plastic, or other approved materials, and players grip them in one hand while using the other arm for maneuvering underwater. The puck is a dense lead disc coated in plastic, weighing about 1.3 kilograms (just under 3 pounds). That weight keeps it firmly on the pool floor and prevents it from floating up during play.
Beyond the stick, every player wears a mask with safety glass or equivalent lenses, a snorkel, fins, a mouth guard, and a protective glove on the playing hand. The glove cannot contain any rigid or sharp reinforcing material. Players also wear headgear fitted with firm ear protectors made of polyethylene or rubber, which shield against accidental kicks from nearby fins. Masks must use a dual-lens design unless a single-lens version has a center support built into the frame.
Player Positions and Tactics
The most common formation is the 2-3-1, which arranges two forwards, two wings, a center, and a full back. Each position has a distinct job, and the constant need to surface for air means players cycle through their roles in waves.
- Forwards stay ahead of the puck, positioning themselves between the play and the goal they’re attacking. They receive passes and drive the puck forward, ideally diving in pairs to create two-on-one advantages against defenders. When not on the attack, they drop back to block passing lanes and disrupt the opposing team’s offense.
- Wings cover the sides of the formation. The “strong side” wing, on the same side as the current play, dives behind the puck to push it forward. The “weak side” wing stays ready to receive a cross-pool pass or engage an opposing player who swings wide.
- Center distributes the puck and prevents opponents from driving through the middle of the formation. This player redirects pressure toward teammates or passes out to wings and forwards.
- Full back acts as the last line of defense, filling gaps wherever they appear. Sometimes called the “stopper,” this player cycles behind the wings and center, plugging holes in coverage. How this rotation works depends on the team’s style and individual preferences.
Fouls and Penalties
Referees officiate from above the water, watching through masks or from the pool deck, and signal fouls by stopping play. For minor or first-time infractions, a referee may award an advantage puck (similar to a free kick). For more serious or repeated violations, the offending player is sent to a penalty box to serve a one, two, or five-minute time penalty, depending on severity.
Common fouls include advancing the puck with your hand, obstructing or barging into opponents, grabbing another player, and lifting or carrying the puck off the pool floor. Handling an opponent draws a two-minute penalty on the first offense, escalating to five minutes for repeated violations. Deliberately removing another player’s equipment earns an immediate five-minute penalty, and a third offense results in ejection from the match. Players serving time penalties cannot be replaced by substitutes, so their team plays shorthanded, just like in ice hockey. Repeated unsportsmanlike conduct or a deliberate major infringement can lead to dismissal for the rest of the game.
What It Does to Your Body
Underwater hockey places unusual demands on the body. Players perform repeated breath-hold dives throughout a match, which over time trains the body to tolerate higher levels of carbon dioxide in the blood. Research published in Undersea and Hyperbaric Medicine found that experienced underwater hockey players showed a significantly blunted breathing response to carbon dioxide compared to non-divers. Their bodies had essentially learned not to panic when CO2 levels rose, allowing them to stay calmer and more efficient during dives.
The same study found that after repeated breath-hold exercises, players’ blood oxygen levels dropped lower than those of untrained subjects, yet they produced less lactic acid. This suggests their muscles had adapted to work more efficiently with limited oxygen, relying less on the anaerobic energy pathways that cause that burning, fatigued feeling. The combination of aerobic fitness, breath-hold tolerance, and explosive underwater sprinting makes the sport physically demanding in a way that few other activities replicate.
International Competition
CMAS, the World Underwater Federation, oversees international underwater hockey competition. World championships are held for both elite and age-group divisions. The most recent age-group world championship took place in July 2024 in Kuala Lumpur, Malaysia, with the next scheduled for 2026. Traditional powerhouse nations include Australia, South Africa, France, New Zealand, and Great Britain, all of which have deep competitive histories in the sport.
The game is played in over 30 countries across six continents. Most nations have their own governing bodies that organize domestic leagues, tournaments, and national team selection. In the UK, the sport still goes by its original nickname “octopush” in some circles, a nod to the eight players originally on each team when the British Navy first developed the game. Despite its niche profile, the community is tight-knit and growing, with clubs in major cities offering beginner sessions for anyone comfortable in a pool.