List of water sports

Water sports encompass a broad range of recreational and competitive athletic activities conducted in, on, or under bodies of water, such as oceans, lakes, rivers, and pools, offering physical exercise, skill development, and enjoyment for participants of all ages and skill levels.^[1][2] These activities can be categorized into several main types, including individual pursuits that emphasize personal technique and endurance, team-based games that require coordination and strategy, and specialized underwater disciplines focused on exploration and breath control.^[2] Individual water sports often include swimming, where athletes propel themselves through water using various strokes in pools or open water; surfing, riding ocean waves on a board; water skiing, being towed behind a boat on skis; wakeboarding, performing tricks while towed on a board; skimboarding, gliding on shallow water or wet sand; paddleboarding, standing on a board and paddling; kneeboarding, riding on knees while towed; personal watercraft riding, operating jet skis; parasailing, being towed airborne behind a boat; and fishing, casting lines from boats or shores.^[2][3][4] Team water sports typically feature water polo, a contact sport played in pools with goals; synchronized swimming (now artistic swimming), choreographed routines combining swimming and gymnastics; rowing, propelling boats with oars in crews; rafting, navigating rapids in inflatable boats; canoeing, paddling canoes often in teams; and kayaking, using kayaks for racing or touring.^[2][5] Underwater and other specialized water sports add further variety, such as snorkeling and scuba diving for observing marine life, freediving for breath-held descents, and sailing or windsurfing harnessing wind on vessels or boards.^[4][6] Many water sports are governed by international federations and featured in major events like the Olympics, where disciplines including swimming, open water swimming, diving, water polo, and artistic swimming are contested under World Aquatics.^[5][7]

Sports on the water surface

Vessel-based sports

Vessel-based sports encompass a diverse array of competitive and recreational activities centered on the propulsion and navigation of boats, canoes, kayaks, and other watercraft across calm or turbulent surfaces, emphasizing teamwork, technique, and environmental adaptation. These sports rely on human-powered, wind-assisted, or motorized mechanisms, and have evolved from ancient transportation methods into structured competitions that test endurance, strategy, and precision. Historical roots trace back millennia, with many achieving Olympic status in the early 20th century, fostering global participation through standardized events and equipment innovations. Canoeing involves paddling a narrow, open-top vessel using a single-bladed paddle, with athletes kneeling and facing forward to propel the craft. In sprint canoeing, competitors race on flatwater courses over distances of 200m, 500m, 1,000m, or 5,000m in single (C1), double (C2), or four-person (C4) boats, focusing on powerful, synchronized strokes for straight-line speed. Canoe slalom, by contrast, requires navigating a whitewater course up to 300m long, passing through up to 25 gates (some upstream) while avoiding penalties for misses or touches, demanding agility and rapid maneuvers in turbulent currents. Canoeing debuted as a demonstration sport at the 1924 Paris Olympics and became a full medal event in 1936 at Berlin, with slalom joining in 1972 at Munich. Equipment includes lightweight fiberglass or carbon-fiber hulls designed for stability and speed, paired with ergonomic paddles featuring asymmetrical blades for efficient pull and recovery. Kayaking employs a double-bladed paddle and a closed-deck vessel where the paddler sits with legs extended, allowing for versatile propulsion in varied conditions. Whitewater kayaking mirrors canoe slalom but uses kayaks for solo (K1) or team formats, emphasizing rolls to right the boat after capsizing and precise gate navigation amid rapids classified by difficulty from Class I (easy) to Class V (expert). Sea kayaking, often recreational yet competitive in marathon races, involves longer, seaworthy kayaks for touring coastal or open waters, prioritizing endurance over 10-100km distances with focus on tidal currents and weather. Like canoeing, kayaking entered the Olympics in 1936 for sprint events on flatwater, with distances matching those of canoe sprint, and slalom variants since 1972. Hull designs vary from short, maneuverable whitewater models (under 3m) to stable sea kayaks (over 5m), all sealed with spray skirts to prevent water ingress. Rowing, also known as crew, utilizes oars in a sweeping motion to drive long, narrow shells through water, with rowers facing backward toward the stern. Sweep rowing features one oar per athlete, arranged in pairs or eights with a coxswain for steering and pacing commands, while sculling uses two oars per person in singles, doubles, or quads without a coxswain. Races cover 2,000m on flatwater, requiring rhythmic strokes divided into catch (blade entry), drive (leg push), finish (blade exit), and recovery phases, with crew formations like bow pairs setting the initial pace. Rowing has been an Olympic sport since its debut at the 1900 Paris Games, evolving from ancient Egyptian transport to modern competitions emphasizing power-to-weight ratios in lightweight classes introduced in 1996. Equipment includes finned hulls for tracking, adjustable riggers to optimize oar leverage, and carbon-fiber oars with spoon-shaped blades for reduced drag. Sailing harnesses wind for propulsion across monohulls or multihulls, with maneuvers like tacking (turning the bow through the wind to change direction) and gybing (turning the stern) critical for upwind and downwind legs in races. Yacht racing classes include one-design fleets like the Laser or 49er, where identical boats emphasize sailor skill, and handicap systems like the International Offshore Rule for varied designs in longer offshore events spanning days or weeks. Wind-dependent tactics involve sail trim adjustments—flattening for gusts or powering up in light airs—and reading shifts to gain lanes, often in fleet, match, or team formats. Sailing competed at the 1900 Paris Olympics, initially as yachting with larger boats, transitioning to smaller dinghies by the mid-20th century for accessibility. Sails, made from durable Dacron or laminates, attach to masts and booms, while hulls feature keels or foils for stability and speed in classes up to 20 knots. Dragon boat racing features teams of 20 paddlers plus a drummer and steerer propelling a colorful, dragon-headed canoe over 200-500m courses, stressing synchronized strokes led by the drummer's cadence for unified power. Originating in ancient China over 2,000 years ago as rituals to avert misfortune and honor figures like poet Qu Yuan, it gained modern sport status with the 1976 Hong Kong International Races, promoting cultural festivals worldwide. Not yet Olympic but featured in Asian Games since 1982, it highlights team harmony and endurance, with boats crafted from teak or fiberglass mimicking mythical serpents. Paddles are straight-bladed for rapid recovery, and hulls measure about 12.5m long for stability in group starts. Rafting entails guiding inflatable rafts through whitewater rivers using paddles, with teams of 4-12 navigating rapids rated by the International Scale (Class III moderate to Class V extreme), focusing on commands for forward, back, or brace strokes to avoid obstacles like rocks or hydraulics. Originating from 19th-century explorations, such as John Wesley Powell's 1869 Colorado River expedition, recreational whitewater rafting surged post-World War II with surplus military rafts, becoming a guided sport by the 1950s on rivers like the Snake or Salmon. Equipment includes self-bailing rafts (8-16ft diameter) made of heavy-duty PVC or Hypalon, paired with Type III-V life jackets and helmets for safety in non-competitive descents up to 50km. Jet skiing, or personal watercraft racing, involves stand-up or sit-down operation of motorized skis for high-speed circuits or freestyle, with formats like sprint ovals (up to 1,000m) or offshore endurance runs. Riders maneuver using body weight shifts for jumps, turns, and wakes, competing in stock, modified, or unlimited classes based on engine modifications (typically 500-1,600cc). Invented in the 1970s by Clayton Jacobson II, with Kawasaki's 1973 model sparking the sport, professional racing organized in the 1980s through bodies like the International Jet Sports Boating Association. Hulls are planing designs for planing at 20+ knots, with impellers replacing propellers for shallow-water agility, though not Olympic, it features in world championships since 1982.

Board and ski sports

Board and ski sports involve participants using boards, skis, or analogous devices to glide across the water surface, propelled by natural elements like waves or wind, or mechanically via towing. These activities demand proficiency in balance, agility, and environmental awareness, fostering personal skill development and often competitive formats ranging from amateur to professional levels. Originating from ancient practices in various cultures, particularly Polynesian wave riding, the category has expanded globally with technological advancements enhancing accessibility and performance. Surfing entails standing on a specialized board to ride ocean swells, employing techniques such as trimming for speed on the wave face or cutbacks for directional changes. Board varieties include longboards (typically 9-10 feet) for graceful maneuvers and shortboards (5-7 feet) for high-performance turns in steeper waves. The sport traces its modern revival to Hawaii in the early 20th century, with wave riding formalized through competitions by the International Surfing Association (ISA), established in 1964.^[8] Windsurfing integrates elements of surfing and sailing, where riders balance on a board equipped with a pivoting mast and sail to capture wind for propulsion across flat water or waves. Techniques range from planing (skimming above the surface) to jibes (turns without losing speed) and aerial loops. Equipment evolution since the 1960s has shifted from rudimentary sailboards weighing over 30 kg to modern composite constructions under 10 kg, improving maneuverability and wind efficiency, as overseen by the International Windsurfing Association (IWA).^[9] Kitesurfing utilizes a controllable inflatable kite attached to a harness, pulling the rider on a small twin-tip board for high-speed runs, jumps up to 15 meters, and rotations. Key maneuvers include kite loops for acceleration and board passes for unhooked tricks, requiring precise bar control for steering. The International Kiteboarding Association (IKA) governs the sport, emphasizing progression from controlled launches to advanced freestyle. Safety protocols mandate quick-release systems to depower the kite instantly, reducing drag-related injuries.^[10] Stand-up paddleboarding (SUP) requires standing upright on a wide, stable board while propelling with a single long paddle, suitable for calm-water touring, fitness paddling, or competitive racing over distances up to 10 km. Balance is maintained through core engagement and subtle weight shifts, with racing variants favoring narrower boards for speed (averaging 10-12 km/h) versus touring's broader designs for stability. Originating from Hawaiian beach boys in the 1940s for photography, SUP has grown under ISA oversight, accommodating all ages and abilities.^[11] Water skiing involves two or one skis clamped to the feet, towed at speeds of 50-60 km/h by a boat, with slalom courses testing precision around 6-10 buoys, jumps over ramps up to 2 meters high, and barefoot variants relying on body grip at 70+ km/h. The International Waterski & Wakeboard Federation (IWWF) standardizes events, highlighting technique over raw power.^[12] Wakeboarding employs a single wide board for boat-towed riding at 20-30 km/h, featuring tricks like ollies (popping off the wake), 360 spins, and rail grabs on fixed obstacles. Bindings secure the feet for edge control, enabling inverted grabs and butters (surface presses). Wakeboarding evolved from water skiing's towing methods in the 1980s, as promoted by the World Wake Association (WWA).^[13] Wakesurfing allows ropeless riding on the boat's stern wake, where participants drop the towline after initial pull and surf the continuous wave using foot steering and body lean, achieving rides over 100 meters. Unlike wakeboarding's emphasis on jumps, wakesurfing prioritizes carving and flow on boards with varying rocker for tail or nose riding. The Competitive Wake Surf Association (CWSA) ranks global athletes, noting its emergence in the 2000s as a freeride alternative.^[14] Skimboarding uses a small, round-edged board (under 1 meter wide) dropped into shallow shorebreak after a sprint, enabling wave catching for spins, shuv-its (board flips), and wraps (wave turns). Techniques focus on thin water flow for speed, with wood or foam cores providing float. The United Skim Tour (UST) organizes professional events, tracing the sport's roots to 1920s Southern California lifeguards.^[15] Bodyboarding positions the rider prone or drop-knee on a flexible foam board (41-43 inches), using hand planes and swim fins for propulsion and steering through tube rides and spins. Fins enable powerful kicks for positioning on breaking waves up to 3 meters. The International Bodyboarding Community (IBC) sanctions world tours, with the sport formalized in the 1970s from ancient paipo practices.^[16] Flyboarding attaches water jets from a linked personal watercraft to a board's soles, propelling riders 10-15 meters airborne for hydrofoil dives and backflips, controlled by foot pressure on nozzles. Invented in 2010, it combines jet propulsion with board balance, with no international governing body as of 2025.^[17] Safety in board and ski sports prioritizes leashes to tether devices and prevent drifting hazards, impact-absorbing wetsuits or helmets to mitigate collision risks with water or obstacles, and spotter protocols during towing to avoid propeller strikes. The WWA advocates pre-session checks on equipment integrity and environmental conditions to minimize drowning or spinal injuries.^[13] Equipment evolution exemplifies adaptation to performance needs; for instance, surfing transitioned from heavy wooden boards (up to 70 kg) in the early 1900s to lightweight fiberglass-reinforced polyurethane foam post-1950s, reducing weight by 70% and enabling sharper designs for better wave control.

Sports in the water

Individual swimming sports

Individual swimming sports encompass a variety of solo disciplines that emphasize personal propulsion through water using the body, fins, or acrobatic entries, promoting endurance, technique refinement, and physical conditioning. These activities range from competitive racing in controlled pools to open-water challenges and rehabilitative exercises, all governed by organizations like World Aquatics for most events. Participants focus on stroke efficiency, breath management, and body positioning to optimize performance and minimize injury risk. Swimming involves propelling the body through water using coordinated arm and leg movements, with four primary competitive strokes: freestyle (crawl), backstroke, breaststroke, and butterfly. Freestyle mechanics feature alternating arm pulls with a flutter kick, allowing continuous forward motion and efficient breathing by rotating the head to the side; backstroke uses a supine position with alternating arms and a flutter kick; breaststroke employs a symmetrical pull-out, kick, and glide for power; and butterfly requires a dolphin kick with simultaneous arm recovery overhead. Breath control is critical across strokes, involving rhythmic exhalation underwater and inhalation during recovery phases to maintain oxygen supply during exertion. In Olympic pool events, distances range from 50m to 1500m for freestyle, with shorter sprints like 50m and 100m emphasizing speed, while longer races like 400m and 1500m test endurance; backstroke, breaststroke, and butterfly are contested at 100m and 200m, and individual medley combines all four strokes equally over 200m or 400m.^[18] Open-water swimming differs from pool events by occurring in natural bodies like oceans or lakes, introducing variables such as currents, waves, and navigation without lane markers, often over 10km distances in Olympics, requiring sighting techniques every few strokes to maintain direction.^[19] Swimming provides unique cardiovascular benefits, enhancing heart and lung efficiency, lowering blood pressure, and improving circulation without joint stress due to water's buoyancy.^[20] Artistic swimming, formerly known as synchronized swimming, includes solo routines where athletes perform choreographed movements to music, blending swimming technique with gymnastics and dance elements. Solo technical routines last about 2 minutes and require specific required elements like lifts and spins, judged on execution, difficulty, and artistic impression, while free solos of 2:30 minutes allow creative freedom without imposed figures.^[21] Breath control is advanced, with swimmers holding air for up to 30 seconds during inverted positions or eggbeater kicks for stability. These routines build core strength and flexibility, contributing to improved cardiovascular fitness through sustained aerobic effort. Finswimming is a speed-based discipline using a monofin or bifins to propel the swimmer underwater or on the surface, governed by the Confédération Mondiale des Activités Subaquatiques (CMAS). In pool events, distances like 50m to 1500m test acceleration and endurance, with apnea (breath-hold) variants adding challenge by limiting breaths; surface swims use freestyle-like arm motions combined with fin kicks for maximum velocity.^[22] Technique emphasizes streamlined body position and powerful undulating kicks to achieve speeds exceeding regular swimming, benefiting cardiovascular health by increasing heart rate and oxygen utilization in a low-impact environment.^[23] Aqua jogging, or deep-water running, simulates land running in chest-deep water using a flotation belt, providing non-weight-bearing cardio training. The motion involves high-knee drives and arm pumps against water resistance, mimicking jogging form without ground impact, ideal for injury recovery or conditioning.^[24] Sessions of 20-45 minutes elevate heart rate comparably to treadmill running while reducing joint stress by up to 90%, supporting cardiovascular improvements and muscle endurance.^[25] Water aerobics consists of choreographed, low-intensity exercises in shallow water, such as leg lifts, arm circles, and jumps, designed for group or solo sessions to enhance fitness and rehabilitation. Performed to music, routines target full-body toning with water's resistance amplifying effort without strain, typically lasting 30-60 minutes.^[26] Benefits include boosted cardiovascular health through increased circulation and reduced blood pressure, plus joint protection via buoyancy, making it suitable for older adults or those with arthritis.^[27] Diving features acrobatic leaps from 1m, 3m springboards, or 5m, 7.5m, 10m platforms into water, scored on takeoff, flight, and entry based on difficulty and execution by seven judges. Individual events require six dives for men and five for women in finals, with mechanics focusing on controlled rotations, twists, and minimal splash entry using pike or tuck positions.^[28] Breath control aids in tucking and somersaulting mid-air, while cardiovascular gains come from repeated high-intensity efforts improving heart efficiency.^[29] In triathlon, the swim leg integrates as the first discipline, covering 1.5km in open water for Olympic distance, using freestyle stroke amid competitors before transitioning to cycling and running. Swimmers navigate buoys and drafts for efficiency, with mechanics prioritizing steady pacing and bilateral breathing to conserve energy for subsequent segments.^[30] The water portion boosts cardiovascular endurance without equipment, aiding overall multisport fitness.^[31]

Team and ball sports

Team and ball sports encompass collaborative aquatic activities conducted in pools or open water, where participants engage in strategic gameplay involving propulsion through swimming, ball handling, and opposition to score points, often with physical contact permitted under regulated conditions. These sports emphasize teamwork, tactical positioning, and endurance, distinguishing them from individual swimming disciplines by their objective-based objectives and equipment like balls or goals. Common examples include water polo, water basketball, water volleyball, and team artistic swimming, each with unique adaptations to the aquatic environment. Artistic swimming (team), formerly known as synchronized swimming team events, involves groups of eight swimmers (with up to four reserves) performing highly synchronized, choreographed routines to music that combine swimming, dance, and gymnastics elements. Routines are divided into technical programs (lasting 2:50 max, featuring required elements like boosts and throws) and free programs (lasting up to 4:00 max, allowing creative interpretation), judged on execution, synchronization, difficulty, and artistic impression by panels of judges. Breath control is essential for prolonged underwater sequences and formations, with the sport promoting teamwork through precise timing and mutual support, enhancing cardiovascular endurance and flexibility. Governed by World Aquatics, team events are featured in Olympics and world championships.^[32][33] Water polo, a high-intensity team sport, originated in the late 19th century in Britain as "aquatic football," invented by William Wilson in Scotland around 1869–1870, with the first formalized rules established by the London Swimming Club in 1876. The sport evolved from rugby-style play in rivers and lakes to structured pool competitions, gaining Olympic status in 1900 and international standardization through FINA (now World Aquatics) in 1908, which adopted English-Scottish rules in 1911 to promote uniformity.^[34] Each team consists of seven players—six field players and one goalkeeper—competing in a 30-meter by 20-meter pool, with matches divided into four eight-minute quarters of actual playing time.^[35] The goalkeeper is confined to the defending half and the two-meter area in front of the goal, cannot take the ball beyond the halfway line, and must release it within the shot clock period, typically 30 seconds for field players but with specific handling limits to prevent stalling.^[35] Fouls are categorized as ordinary (resulting in a free throw from the foul spot), exclusion (player removed for 20 seconds or until a counter-foul, for aggressive actions like holding or striking), or penalty (shot from five meters for deliberate goal-area violations).^[35] The two-meter rule functions as an offside provision, prohibiting offensive players from entering the opponent's two-meter zone unless they are behind the ball or in possession, ensuring defensive space and promoting fluid play.^[36] Water basketball adapts basketball principles to shallow pools, typically using floating hoops and inner tubes for flotation, with teams of five players (four in the water) passing and shooting a ball to score in elevated baskets, often within a 10- to 12-foot court marked by lanes. Developed in the mid-20th century as a recreational variant combining water polo and basketball elements, it emphasizes dunking adaptations where players can submerge the ball only briefly for shots, prohibiting prolonged submersion to avoid fouls.^[37] Court setups feature a central dividing line, with three-point shots awarded from beyond a designated arc (usually three meters from the basket), mirroring land basketball but adjusted for water resistance and no-dribbling rules—players advance the ball via passes or two-step swims.^[37] Games last two 10-minute halves, with three personal fouls leading to disqualification, and stalling violations (failing to advance after a 10-count) resulting in turnover. Water volleyball, played in waist-deep pools with a net spanning the width (typically 6 meters wide by 1 meter high above water), involves teams of four to six players spiking and blocking a volleyball over the net, scoring on rallies similar to beach volleyball but adapted for non-treading propulsion.^[38] Originating as a leisure activity in the early 20th century, it gained popularity in recreational settings post-World War II, with rules emphasizing that the ball must remain above water and allowing underhand or sidearm serves to account for buoyancy challenges.^[39] Matches are played to 11, 15, or 25 points (first to win by two), with no rotation restrictions in smaller formats, and spiking permitted from any position provided the ball crosses vertically over the net without carrying or double-hits.^[38] In pool setups, the court measures about 8 meters by 4 meters per side, promoting quick transitions and tactical net play without specialized equipment beyond the standard volleyball.^[38]

Sports under water

Recreational diving activities

Recreational diving activities encompass a range of non-competitive underwater pursuits that emphasize personal exploration, leisure, and interaction with aquatic environments, typically employing breathing aids or breath-holding techniques to access depths beyond surface swimming. These activities allow participants to observe marine life, underwater landscapes, and geological features in a relaxed manner, often in coastal or open-water settings accessible to amateurs with basic training. Unlike competitive sports, they prioritize enjoyment and skill-building over timed performance or opposition. Snorkeling involves swimming on or near the water's surface while wearing a diving mask, a J-shaped tube called a snorkel for breathing, and often swim fins for propulsion, enabling extended viewing of shallow underwater scenes without full submersion. This activity is ideal for beginners, as it requires minimal equipment and no formal certification, allowing participants to observe coral reefs, fish, and seagrasses at depths of 1 to 5 meters by floating face-down.^[40] The snorkel extends the airway to facilitate nasal or oral breathing while keeping the face in the water, though it limits dive duration due to increased dead space in the breathing path.^[41] Scuba diving utilizes self-contained underwater breathing apparatus (SCUBA), a backpack-mounted tank of compressed air or nitrox connected to a regulator that delivers breathable gas on demand, permitting prolonged submersion independent of surface air supplies. Recreational scuba is limited to no-decompression dives, with a maximum depth of 40 meters (130 feet) to minimize risks like nitrogen narcosis, and requires certification from organizations like NAUI or PADI, starting with entry-level Open Water courses that typically train divers to depths of 18 to 30 meters, depending on the certifying organization such as PADI or NAUI.^[42] Advanced certifications, such as those for deep or night diving, build on this foundation, emphasizing buoyancy control, equipment handling, and navigation in varied conditions like currents or low visibility.^[43] Free-diving, also known as breath-hold diving, relies on a single inhalation of air to achieve controlled descents and ascents without breathing apparatus, focusing on relaxation, lung capacity, and physiological adaptation to depth.^[44] Participants employ techniques like the Frenzel or Valsalva maneuver for equalization—equalizing middle ear pressure by gently blowing against a closed glottis or swallowing—to counteract increasing hydrostatic pressure during descent, typically every two feet to prevent barotrauma.^[45] Depths for recreational free-divers often range from 10 to 30 meters, with training emphasizing breath-hold times of 2-4 minutes and recovery protocols to avoid shallow-water blackout.^[46] Underwater photography extends these activities by incorporating specialized equipment to document marine subjects, serving as a creative pursuit that enhances observation skills during snorkeling, scuba, or free-diving sessions.^[47] Cameras are housed in waterproof enclosures rated to at least 40 meters for recreational use, protecting against pressure while allowing capture of coral formations, fish behaviors, and wrecks through techniques like wide-angle lenses for close-focus wide-field shots or strobes for color correction in low-light depths.^[48] Safety in recreational diving hinges on protocols like the buddy system, where pairs of divers monitor each other for issues such as equipment failure or fatigue, ensuring mutual assistance without solo dives.^[49] Decompression awareness is critical for scuba, involving adherence to no-decompression limits via dive computers or tables to prevent bubbles forming in tissues from rapid ascents, with conservative profiles recommended—such as staying well under maximum times at depth.^[50] Environmental guidelines for these activities stress minimal impact on ecosystems, particularly in sensitive areas like coral reefs, where participants follow "no-touch" rules to avoid physical damage from fins, hands, or gear that can break fragile structures or disrupt habitats.^[51] Organizations advocate buoyancy control in scuba and free-diving to prevent sediment stirring, along with prohibitions on collecting specimens, promoting "look but don't touch" to preserve biodiversity.^[52]

Competitive underwater sports

Competitive underwater sports encompass organized competitions conducted entirely beneath the water surface, typically in pools or open water, where participants rely on breath-holding techniques or limited breathing apparatus to engage in timed, scored events involving speed, accuracy, or team-based objectives. These sports demand advanced apnea skills, often building on foundational abilities from recreational diving activities. Governed primarily by the Confédération Mondiale des Activités Subaquatiques (CMAS), the international federation for underwater sports, these disciplines emphasize safety, precision, and physical endurance while adhering to strict rules on equipment and conduct. Underwater hockey, also known as octopush, is a team sport played at the bottom of a swimming pool where two teams of six players each use short wooden sticks to push a puck weighing 1.3 kg (±0.2 kg) into the opponent's goal, which is a circular depression in the pool floor. Each team may have up to four substitutes, allowing continuous rotation to manage breath-holding limits. Matches consist of two 15-minute halves separated by a two-minute break, with players resurfacing as needed for air; physical contact is permitted but regulated to prevent injury. The sport's rules, standardized by CMAS, require pools of at least 25 meters in length and 12 meters in width with a depth of 2 to 4 meters to ensure safe play. CMAS has organized world championships since 1980, promoting the sport's growth across Europe, Australia, and North America.^[53][54] Underwater rugby involves two teams competing to carry a negatively buoyant, torpedo-shaped ball into wire goals located at the pool bottom, requiring players to wrestle and pass underwater in a three-dimensional space. Teams consist of six players in the water at any time, drawn from a roster of up to 15, including substitutes for fatigue management during breath-hold plays. Invented in Cologne, Germany, in 1961 as a training exercise for divers, the sport was officially recognized by CMAS in 1978, with the first European Championships held that year in Malmö, Sweden, and the inaugural World Championship in 1980. Games last two 10-minute halves with a short interval, scored by successful ball placements in the goal; fouls such as excessive holding result in free passes. CMAS rules mandate pools of 12 to 18 meters in length and 8 to 12 meters in width, and 3.5 to 5 meters in depth to accommodate the contact nature of the game.^[55][56][57] Underwater target shooting tests competitors' accuracy with spearguns fired on stationary targets while holding breath, performed in apnea without scuba assistance. Events include individual precision shooting, where athletes fire multiple shots at circular targets from distances of 2 to 5 meters, and relay formats emphasizing speed and teamwork. Targets are placed at the pool bottom, typically at depths of 1.8 to 5 meters, with scoring based on shot proximity to the center—10 points for a direct hit, decreasing to 1 point at the edges, and 0 for misses—measured via graduated scales. CMAS regulations require pools of at least 10 by 25 meters, and competitions feature practice sessions before events; in case of ties, shoot-offs determine rankings. World and continental championships, organized by CMAS since the 1970s, focus on standardized mass-produced spearguns to ensure fairness.^[58][59][60] Finswimming competitions feature underwater speed events where athletes propel themselves using fins in breath-hold (apnea) disciplines, such as 50-meter or 100-meter immersion swims, alongside surface variants. Participants use equipment like monofins for streamlined underwater propulsion or bifins for versatility, with masks and snorkels permitted only for surface breathing recovery in hybrid events. Underwater apnea events require full submersion after an initial surface glide, testing explosive power and glide efficiency without arm pull. CMAS rules specify 50-meter pools for international events, with 25-meter pools used for some regional competitions, distances scaled by age groups—up to 800 meters for endurance—and relays involving four swimmers per team. The sport has been under CMAS governance since the 1950s, with world championships held biennially since 1976, highlighting speeds exceeding 2 meters per second in elite apnea categories.^[61][62][63] Competitive spearfishing entails timed hunts for fish using spearguns in open water, scored by total weight of catch within ethical and regulatory limits, emphasizing selectivity and sustainability. Events are conducted in apnea, with competitors targeting abundant species while adhering to minimum size thresholds and bag limits set by local authorities to prevent overfishing. CMAS defines rules prohibiting scuba use, motorized aids, or lights, and requires all catch to be for consumption or charity, promoting conservation through selective harvesting. Tournaments, such as CMAS World Championships since 1969, last 4 to 8 hours per day over multiple days, with teams or individuals competing in designated zones; ethical guidelines mandate immediate dispatch of speared fish to minimize suffering. Historical roots trace to ancient practices, but modern competitions under CMAS began in the mid-20th century, focusing on skill over volume.^[64][65][66]