Swimming 15 Meter Underwater Rule

Swimming 15 Meter Underwater Rule

Most strokes require the swimmer to have some part of their body above the water for the first 15 meters of any race and the first 15 meters after any turn. This rule is followed by most swimming associations including: FINA, USA Swimming, NFHS, and ISA Swimming. The NCAA allows the use of underwater videos to make sure that swimmers are not underwater for more than the allowed 15 meters.

What Is the 15 Meter Underwater Rule in Swimming?

The NCAA defines the 15-meter rule as a rule in which a swimmer must break the surface of the water by the 15-meter mark. This rule is enforced at the start of a race as well as after each turn. If this specific rule is broken, it can lead a swimmer to be disqualified. In order for referees and swimmers to easily ensure that this rule is followed, the 15-meter mark must be marked on both sides of the pool.

The most common and effective way to depict the 15-meter mark is through the use of colored lane lines. At the 15-meter mark on both the start and turn end of the pool, the lane lines should change to a distinct color that is easy for a swimmer to see underwater, or if the lane lines alternate in color, the 15-meter mark can be when the lane lines become one solid color.

Why Is the 15 Meter Rule Enforced?

As with most swimming rules, the 15-meter rule was created to ensure that all races were fair. When a swimmer is underwater, it helps to reduce drag and therefore makes a swimmer faster. However, not all swimmers can stay underwater for the same amount of time and so without the 15-meter rule, the swimmers who could stay underwater the longest had an unfair advantage.

Since all swimmers have to break the surface by 15 meters, the races become more fair. This isn’t to say that having a strong ability to reach the 15-meter mark in a pool doesn’t put a swimmer at an advantage. Not all swimmers even make it to the 15-meter mark, and having a strong underwater ability can greatly benefit those swimmers even by giving them a head start. Typically this is most helpful in stroke races and even distance freestyle races to a lesser extent.


Staying underwater has been proven to help a swimmer have faster starts and turns and can even help a swimmer earn a best time. However, if a swimmer stays underwater longer than the 15-meter mark, they will be disqualified.


What is the 15-meter underwater rule in swimming?

The 15-meter underwater rule in swimming states that no swimmer may remain underwater in a race past the 15-meter mark. This rule not only applies to the start but also applies after each turn. Typically a swimmer can identify the 15-meter marker by watching the lane lines. The lane lines may either change color or switch from alternating colors to solid colors at the 15-meter mark, after which the swimmer must break the surface. This rule was put into place as swimming underwater helps to reduce drag and gives swimmers a serious advantage by speeding up their starts and turns and helping them to improve overall times.