Swimming Rules & Regulations

Competitive swimming is a sport that combines technique, speed, and endurance across four primary strokes: freestyle, backstroke, breaststroke, and butterfly. Each stroke has specific rules that swimmers must follow to ensure fairness and maintain the integrity of competition. Governing bodies like World Aquatics (formerly FINA) and USA Swimming set and update these rules regularly.

This guide from the SwimOutlet swim team provides an overview of the current rules for each stroke, event type, starts, turns, finishes, and common disqualifications — everything both new and seasoned swimmers need to be prepared for the competitive swimming environment.

Competitive Swimming Events

Competitive swimming features four individual strokes plus the individual medley (IM) and relay events. Swimmers compete across a range of distances in both short course (25-yard or 25-meter pools) and long course (50-meter pools). For more on pool types, see our swimming pool dimensions guide.

The 15-Meter Rule (All Strokes)

One of the most important rules in competitive swimming applies to every stroke: after every start and turn, the swimmer's head must break the water surface by the 15-meter mark (or 15 yards in SCY pools). This rule limits how far swimmers can travel underwater using streamline position and dolphin kicks, ensuring the competition remains a surface swimming event. Exceeding the 15-meter limit results in immediate disqualification.

Most competitive pools have a visible marking — either on the lane lines (a color change in the floats) or on the pool deck — at exactly 15 meters from each wall to help swimmers and officials judge compliance.

Freestyle

Freestyle, also known as the "front crawl," offers the most flexibility in technique and is typically the fastest stroke. The key rules are minimal compared to other strokes:

• The swimmer may use any stroke — technically, "freestyle" does not mandate a specific technique. However, nearly all competitive swimmers use the front crawl because it's the fastest.
• Swimmers cannot push off the bottom of the pool or pull on the lane lines.
• Some part of the swimmer's body must touch the wall at each turn and the finish.
• Swimmers may use flip turns (somersault turns) or open turns.
• The head must break the surface by the 15-meter mark after each start and turn.

Common freestyle disqualification reasons: Walking on or pushing off the bottom, pulling on the lane line, not touching the wall at a turn, and submerging past the 15-meter mark.

Backstroke

Backstroke is the only stroke that starts in the water and is swum entirely on the back. The primary rules are:

• Swimmers must remain on their back at all times, except when executing a turn.
• The race starts in the water — swimmers hold the gutter, starting block grips, or the touchpad with both hands, with feet on the wall and toes below the water surface.
• For flip turns, the swimmer may rotate past the vertical (onto their stomach) to initiate a continuous turning action. The turn must be initiated by a pulling arm motion — not a kick — and must be one continuous motion. Once the swimmer leaves the wall, they must be on their back.
• At the finish, the swimmer must be on their back when they touch the wall. Rolling onto the stomach before the touch is a disqualification.
• The head must surface by the 15-meter mark after the start and each turn.

Common backstroke disqualification reasons: Not being on the back at the finish, rotating past vertical without initiating a continuous turn, submerging past the 15-meter mark, and performing multiple arm pulls while on the stomach during a turn.

Breaststroke

Breaststroke has the most detailed set of rules of any competitive stroke. It requires synchronized, simultaneous arm and leg movements and follows a strict stroke cycle:

• The stroke cycle consists of one arm pull followed by one kick, in that order. Pulling twice or kicking twice within one cycle is illegal.
• The swimmer's head must break the surface of the water at least once during each stroke cycle.
• Arms must move simultaneously and in the same horizontal plane — no alternating arm motions.
• Hands must be pushed forward from the breast on, under, or over the water surface. Elbows must remain in the water except at the turn and finish.
• Feet must be turned outward during the propulsive part of the kick. Flutter kicks (freestyle-style), butterfly/dolphin kicks, and scissor kicks are not allowed during the stroke.
• At all turns and the finish, the swimmer must touch the wall with both hands simultaneously. The hands must be separated but can be at different heights above or below the water.

The Breaststroke Pulldown

After the start and after each turn, the swimmer is allowed one special underwater sequence before surfacing:

1. One full arm pull — the hands may extend all the way back past the hips (beyond the normal stroke limit).
2. One downward dolphin kick (the only time a dolphin kick is legal in breaststroke).
3. One breaststroke kick.
4. The head must break the surface before the hands turn inward at the widest part of the second stroke.

This "pulldown" or "pullout" sequence is one of the most technically specific moments in all of competitive swimming. Getting the sequence wrong — such as taking two dolphin kicks or two arm pulls underwater — is a common disqualification.

Common breaststroke disqualification reasons: Flutter or dolphin kick during the stroke, alternating arm movements, two pulls or two kicks in one cycle, head not breaking the surface during a stroke cycle, one-hand touch at the turn or finish, and illegal pulldown sequence (extra dolphin kick or extra pull).

Butterfly

Butterfly evolved from breaststroke in the 1950s and shares many of its rules about simultaneous movement. The primary rules are:

• Arms must pull and recover simultaneously — both arms move together underwater during the pull phase and recover forward over the water surface together. Alternating arm movements are illegal.
• Legs must kick simultaneously using a dolphin kick (up-and-down motion). Flutter kicks (alternating), scissor kicks, and breaststroke kicks are not allowed.
• After each start and turn, the swimmer may take as many dolphin kicks as desired underwater, but the head must surface by the 15-meter mark. The first arm pull must bring the swimmer to the surface.
• At all turns and the finish, the swimmer must touch the wall with both hands simultaneously. The hands do not need to be at the same level above or below the water, but the touch must be simultaneous.

Common butterfly disqualification reasons: Alternating arm movements, alternating or scissor kicks, underwater arm recovery (arms coming forward under the water instead of over), one-hand touch at the turn or finish, and submerging past the 15-meter mark.

Individual Medley (IM)

The individual medley combines all four strokes in a single race. The swimmer completes one-quarter of the total distance in each stroke, in this fixed order:

1. Butterfly
2. Backstroke
3. Breaststroke
4. Freestyle

The rules for each stroke apply during their respective segment. Key IM-specific rules include:

• Each segment must be finished with the legal touch for that stroke: two-hand simultaneous touches for butterfly and breaststroke, on-the-back touch for backstroke, and any-part-of-body touch for freestyle.
• The backstroke-to-breaststroke transition is the most scrutinized: the swimmer must touch the wall while still on their back (no backstroke flip turn is allowed at this transition). After touching, the swimmer pushes off on their chest to begin breaststroke.
• In the IM, freestyle means any stroke other than butterfly, backstroke, or breaststroke. So the freestyle leg cannot be legally swum using any of the other three strokes.
• Swimming the strokes out of order results in disqualification.

Relays

Relay events feature four swimmers per team, each swimming one-quarter of the total distance. There are two types:

Freestyle Relay

All four swimmers swim freestyle. The first swimmer starts from the block with a standard dive; the remaining three swimmers must wait until their teammate touches the wall before leaving the block. Leaving early — even by a fraction of a second — results in a disqualification for the entire team.

Medley Relay

Each swimmer swims a different stroke, in this order:

1. Backstroke (starts in the water)
2. Breaststroke
3. Butterfly
4. Freestyle

Note the order is different from the individual medley. The first swimmer (backstroke) starts in the water; the remaining three swimmers dive from the blocks. As with freestyle relays, the incoming swimmer must touch the wall before the next swimmer leaves the block.

Starts

The start of a race follows a standard sequence:

1. The referee signals swimmers to the blocks with a series of short whistles.
2. A long whistle signals swimmers to step onto the starting block (or enter the water for backstroke).
3. The starter gives the command "Take your mark" — swimmers assume their starting position.
4. When all swimmers are motionless, the starting signal (a beep or horn) sounds.

For freestyle, breaststroke, and butterfly, swimmers dive from the starting block. For backstroke, swimmers start in the water holding the block grips with feet on the wall. A false start — leaving the block before the signal — can result in disqualification. Under the current "one-start rule" used by USA Swimming and World Aquatics, any swimmer who false starts is immediately disqualified.

Turns and Finishes

Turns and finishes are closely watched by officials and are a leading cause of disqualifications. Here's a summary of the requirements by stroke:

Essential Gear for Competitive Swimming

Having the right gear makes training more effective and competition days smoother. Here's what every competitive swimmer needs:

• Swim goggles — Essential for clear vision and eye protection. See our goggles guide for help choosing.
• Swim caps — Reduce drag and keep hair manageable. Read our swim cap guide.
• Women's competition swimwear — Performance suits designed for racing and training.
• Men's competition swimwear — Jammers, briefs, and tech suits for male swimmers.
• Tech suits — High-performance compression suits for race day.
• Training aids — Kickboards, paddles, and fins for drill work and conditioning.

For beginner-friendly workouts to practice your strokes, check out our beginner swim workouts guide.

FAQs

What is the 15-meter rule in swimming?

After every start and turn in competitive swimming, the swimmer's head must break the water surface before the 15-meter mark (or 15 yards in SCY pools). This rule applies to all four strokes and limits how far a swimmer can travel underwater using streamline and dolphin kicks. Exceeding the 15-meter limit results in disqualification.

Why do breaststroke and butterfly require two-hand touches?

Both breaststroke and butterfly are defined by simultaneous, symmetrical movements. The two-hand touch at turns and finishes enforces this symmetry — it ensures the swimmer is completing the stroke properly and not gaining an advantage by reaching with just one hand. Freestyle and backstroke, which use alternating arm motions, only require any part of the body to touch the wall.

What is a DQ in swimming?

DQ stands for "disqualification." It means the swimmer committed a rule violation observed by an official, so their time does not count and they are not eligible for placement in that event. Common DQ reasons include false starts, one-hand touches in breaststroke or butterfly, not being on the back at the backstroke finish, illegal kicks, and submerging past the 15-meter mark.

Can you swim any stroke in a freestyle race?

Yes — "freestyle" means the swimmer may use any stroke. However, in the freestyle leg of an individual medley (IM) or medley relay, the swimmer must use a stroke other than butterfly, backstroke, or breaststroke. In standalone freestyle events, any stroke or combination of strokes is legal (though virtually all swimmers use the front crawl because it's fastest).

Why is the medley relay order different from the individual medley?

In the individual medley, the order is butterfly, backstroke, breaststroke, freestyle. In the medley relay, the order is backstroke, breaststroke, butterfly, freestyle. The relay starts with backstroke because that stroke requires an in-water start — the backstroke swimmer is the only one who can begin in the water, so they go first. The IM order puts butterfly first because it's the most physically demanding stroke and benefits from a fresh dive start.

What happens if a relay swimmer leaves early?

If a relay swimmer dives off the block before their incoming teammate touches the wall — even by a fraction of a second — the entire relay team is disqualified. Officials use electronic timing systems and relay exchange platforms to detect early takeoffs with extreme precision.

How many dolphin kicks are allowed underwater?

In freestyle, backstroke, and butterfly, swimmers may take as many dolphin kicks as they want after the start and each turn — as long as they surface before the 15-meter mark. In breaststroke, only one downward dolphin kick is permitted during the pulldown sequence after the start and each turn, and it must occur after the arm pull and before the breaststroke kick.

More Resources

These rules are a general summary and can vary depending on the governing body for each meet. For more detailed rules, refer to the following resources:

World Aquatics Swimming Rules
USA Swimming Rules
FINA Masters Swimming Rules
Channel Swimming Rules & Regulations

This guide is written and maintained by the SwimOutlet swim team — competitive swimmers, certified officials, and coaches with decades of combined experience. Rules referenced in this guide are based on current World Aquatics and USA Swimming regulations. While every effort is made to keep this information accurate, always consult the official rulebook for the governing body of your specific meet. For more swimming resources, explore our pool dimensions guide, beginner swim workouts, and water temperature guide.