Water covers more than 70 percent of the earth, making maritime operations a must-have capability for any competent military.

Besides having the strongest Navy in the world, the U.S. military possesses potent maritime special-operations resources, with the majority of its special-operations units having some combat diving capability.

Marine Raiders and Reconnaissance Marines have different training pipelines but go through the same dive school in Panama City.

Navy Marine Corps combat diver
A Navy special amphibious reconnaissance corpsman, left, and a reconnaissance Marine in underwater gear during a Marine combat diving course in Okinawa, May 20, 2020 (U.S. Marine Corps/Cpl. Savannah Mesimer)

Army Green Berets have dedicated combat diver teams, and some Rangers go through the arduous Special Forces Underwater Operations School in Key West, Florida, one of the most challenging courses in the Army, where even special operators wash out.