Historically, the United States Marine Corps has been the main amphibious combat arm of the United States military. As such, the ability to swim in dangerous and difficult circumstances has always been an important qualification for a Marine. Marine Corps recruits are required to pass swim qualifications in Phase 3 of basic training -- in weeks 10 to 13 -- and must re-qualify at least once every three years.

Modified Regulations

At the time of this writing, the most recent update to the Marine Corps' swim qualifications took effect on April 15, 2011. The new qualifications place renewed emphasis on the ability to survive in the water with full combat gear. Marines are eligible for three levels of swim qualifications, basic, intermediate and advanced. Each of these levels requires a swim test wearing the full combat uniform, including combat boots. The basic qualification requires Marines to remove their gear while submerged in shallow water and to swim 25 meters in full gear. More advanced levels require jumping from a tower into deep water with full gear, treading water in full gear and swimming 250 meters in full gear.