Here's a Breakdown of the Combat Swim Stroke

A Marine recruit conducts swim qualification.
A U.S. Marine Corps recruit with November Company, 4th Recruit Training Battalion, conducts swim qualification at the combat training pool on Marine Corps Recruit Depot, Parris Island, S.C., Sept. 16, 2020. After demonstrations, recruits are tested on their ability to jump into deep water, shed proper equipment, and tread water in full utilities. (U.S. Marine Corps Photo by Cpl. Shane Manson)

"What is the best technique for swimming with fins?" is one of the most frequently asked questions I receive from future and active-duty military personnel. Most are looking for the most efficient way to swim with fins in challenging special operations training such as Navy SEALs, EOD/diver, Army RangersGreen BeretsUSMC RECON, Air Force PJs and others.

What is the Combat Swimmer Stroke?

The combat swimmer stroke is a relaxing and super efficient swim stroke that is an updated version of the traditional sidestroke. Actually, the CSS is a mix of the sidestroke, freestyle and breaststroke in the following ways:

1. Freestyle

The top arm pull of the CSS is the same as arm pulls in freestyle. Breathing after the top arm pulls in the CSS is the same as in freestyle.

2. Breaststroke

The bottom arm pull is the same as the breaststroke arm pull.

3. Sidestroke

The overall look is the same as the side-stroke in the CSS, because you are on your side and using the scissor kick.

Put this mix all together, and you have the CSS in this sequence:

Top arm pull, bottom arm pull, breathe, kick, recover arms overhead, glide.

The stroke can be broken down using the following images.

The start

In a big squat position against the wall, push off and stay as streamlined as possible as you glide at least 5-10 yards off the wall. Place your hands on top of each other, place your biceps on your ears and lock out your arms -- streamlined positioning like a rocket.

500yd Combat Swimmer Stroke in 7 Minutes

The glide

With a big double arm pull, add the other 3-5 yards to your glide by pulling with your back, biceps and pushing water with your arms, using your triceps.

The arm movement

After the arm pull, it is time to breathe. Twist and breath, then start using the top arm pull as shown. Notice both arms recover together forward, but the top arm pulls from overhead all the way to your hips (similar to a freestyle stroke). Then the bottom arm pulls a half stroke (similar to the breaststroke), and both arms recover together. Breathe as the top arm completes its pull, and the bottom arm begins its pull.

The kick

Use the scissor kick and time your kicks so your top leg always goes forward (no matter what side you are on). You should kick just after both arms have pulled and are recovering, adding more glide to each stroke.

The object to the CSS without fins is efficiency; you should try to get across a 25-meter pool in as few strokes as possible. If you are doing more than 10 strokes per length, you are working too hard. The fastest and best swimmers get across a 25-meter pool in 3-5 strokes.

When you find yourself in water with a lot of distance to cover, the CSS will serve you well, especially when you are wearing fins. You will tire less quickly if you learn to perform this stroke properly.

Whether you are a beginning swimmer or an aspiring special operator, this stroke can help you efficiently move through the water with or without fins.

More Special Operations fitness articles:

Super Efficient Combat Swimmer Stroke (CSS)

More swimming articles:

Learn more about available Special Operations opportunities.

Stew Smith is a former Navy SEAL and fitness author certified as a Strength and Conditioning Specialist (CSCS) with the National Strength and Conditioning Association. Visit his Fitness eBook store if you're looking to start a workout program to create a healthy lifestyle. Send your fitness questions to

Want to Learn More About Military Life?

Whether you're thinking of joining the military, looking for fitness and basic training tips, or keeping up with military life and benefits, has you covered. Subscribe to to have military news, updates and resources delivered directly to your inbox.

Story Continues