Lance Cpl. Amber Martinez executes a ‘side stroke’ during the testing portion of the Advanced Swim Qualification Course at Ramer Hall, Quantico, Virginia, April 11, 2014. (Cpl. Christina O'Neil/U.S.

It’s like being right- or left-handed: one side will feel more comfortable when you learn this military swim test stroke. The elementary sidestroke or the combat sidestroke (here’s video showing the ...