By: Naval Special Warfare
Posted: March 4, 2020

The overarching theme of these nine items is that if you want to improve your Combat Sidestroke (CSS) Physical Screening Test (PST) swim, you have to go back to the basics. This applies to you if you are a new swimmer trying to break into the 9’s or if you are a more experienced swimmer who wants to turn his 7:50 into a sub 7:30. How you learn is equally as important, as illustrated with the first four elements of this list. The time spent on the fundamentals and on the drills in the official CSS video and the CSS guide is the best investment you can make in your improvement. The resources are all right here on SEALSWCC.COM. Don’t just watch the CSS video, and don’t merely read the CSS guide. Instead, study them.

Swimming remains a great way to increase your overall fitness without introducing serious risk. Focus on technique, and the speed will come. Make sure you have two good sides to swim on, and the better you are at all strokes, the better you will become at any one of them, since all of the elements of propulsion in water are ultimately related.


This is the most frequent mistake and the one that will affect your success the greatest. Poor technique is the number one mistake that will keep you from passing the PST. Focus on perfecting your technique, every component of it, speed will come. The quickest way to become a faster swimmer is by improving your technique. Technically correct swimming must be taking place at all times, especially once you become tired and fatigued.


If you are swimming on one side, you are unable to conduct a fast open turn, and you will burn out the same set of muscles because the stroke is not symmetrical. It has a left and right variation. When you swim like this, you are trading as much as 20 percent of your potential in exchange for the laziness of not developing the other side. Always swim 50/50. An easy way to do this is to face one side of the pool the entire time. This applies to freestyle as well. You should be able to breathe bilaterally and symmetrically. Do not swim flat; rotation is very important, so drive with your hips and core to increase power and efficiency.


There are two fast parts of any pool, and one slow part. The slow part is the middle, and the fast parts are the walls. On swim critiques, it is frequent to see swimmers going gangbusters in the middle, only to throw it all away once they approach the wall. What you should be considering is that your performance at both those walls has twice the impact on your time that the CSS stroke in the middle has. Items to consider under this section include:

  1. Is my streamline strict and perfect? One wrist over the other wrist, your biceps are squeezing your ears, be as long as possible in the water, and have the least amount of resistance possible.
  2. Is my turn fast and properly executed? You will know your technique was sloppy if you saw the far wall. When you are at the wall, spend as little to no time on the wall. 
  3. Am I using the correct mechanics in my double arm pull? (Breaststroke Pullout) Am I executing it at the right time?


Let the clock decide which stroke rate is appropriate when evaluating your stroke count. Focus on being efficient and mindful of the clock. Just because you're taking more strokes, doesn't mean you're going any faster. We want to go fast with the lowest number of strokes to become efficient in the water.


One of the basic principles of how swimming works is that you can only go forward if you push water back. Taking that further, whichever way you move the water, you go the opposite way. The long, slow, straight-armed pull that many candidates begin with is the least efficient part of the stroke if measured by that basic principle. Because there’s only a small percentage of time during it when the palm is facing the back wall. The rest of the time it’s either pushing down (raising you up, out of the water) or as it completes, pulling you under.

The effect this produces is called loping, which means you are going to rise and sink. Because it extends the underwater recovery time, it also means you will be “caught short,” with nothing out front for a longer period. We want front quadrant swimming taking place. This is an avoidable waste of time, distance and energy. The sprinter’s sidestroke pull is categorically superior, because it operates in a more horizontal plane (like scooping poker chips off a table), and takes far less time, so it naturally shortens recovery. It is the only way you will swim at Naval Special Warfare Preparatory School. Before you wonder if you will get tired faster, you won’t. Because you will be breathing at a proportionally faster rate.

The long, slow, straight-armed pull that you might begin with, has a small range of motion in front of the shoulder. This makes it the least efficient part of the stroke if measured by that basic principle. The straight-arm pull is inefficient because there’s only a small percentage of time during the swim when your palm is facing the back wall – propelling you forward. The rest of the time your palm is either pushing down (raising you up, out of the water) or as it completes, pulling you under.


The CSS guide has an excellent depiction of a good streamline. The fastest way you can move in the water is in the streamline position. The performance of a streamline is not linear. A 100 percent correct streamline is 100 percent effective. A 99 percent correct streamline is 65 percent effective. If you are not assuming the streamline position correctly, you might have some shoulder flexibility issues holding you back. Here is a simple stretch you can do:

  1. Stand about 18 inches from a wall
  2. Lean into the wall with your hands high in a streamline position
  3. Walk back a bit and lean into it
  4. Adjust the stretch so that you feel it in the rear delts and lats

You should be hitting a strict streamline off every wall, and at the top of every stroke cycle. Because this is the fastest you can go in the water, you need to spend as much time in that position as possible. Work on increasing your range of motion, which can help minimize injuries. Elements of a good streamline:

  1. Wrist-over-wrist
  2. Top thumb wraps the bottom hand
  3. External rotation of the shoulders to generate torque and narrow the shoulders
  4. Biceps should be squeezing the ears


The hybrid kick is half scissor kick/half breaststroke kick, which is wrong. The problem with this is that it’s made from nothing whole. If you are doing a scissor kick, which is the correct kick to execute, make sure it’s a correct powerful scissor kick. The top leg always goes forward and the bottom leg always goes back to help drive you onto your stomach where you are strongest. You should be practicing kicking with a kickboard and without, using a lead arm/trail arm technique on both sides


There is plenty of opportunity to misinterpret the timing of CSS, especially if you are making the second pull last a lot longer than it should. The mistake you make here is to breathe during that second pull. If you are doing that, it is far too late in the stroke cycle. It’s the first pull that should rotate you to breath. A checkpoint you can use is one arm fully extended out front, and the other fully extended behind you. If you are breathing late, you are spending more time “short” in the water, and this means you are slowing down. This is difficult to repair, and is resolved with mindful practice. Breathe when you are pushing water, and have your face in the water during recovery. Timing issues result in sluggish, paused, and consequently slow swimming.


This is arguably the single most damaging mistake you can make. Correct breathing takes place about an inch from the waterline, with one wet ear, and one wet eye. This means one eye in the water and one out. If you aren’t seeing a piece of the underwater world during your breath, you are lifting your head too far out of the water. The consequence of this is your hips drop. That turns your entire torso into a hydrodynamic brake that works against your kicks and pulls. The crown of your head should always face your intended direction of travel. Minimize the time it takes to breathe. Only exhale underwater, and make you inhale right at the surface: sharp, full, and fast.