Second phase is the dive phase portion of BUDs. It also builds teamwork, but it starts to create a much greater learning process for the guys going through. The majority of the evolutions that cause the students the most problems is the water work. If a guy is not comfortable in the water, then he’s not really cut out to be a frogman. He’s gotta keep his head about him if something goes wrong with his dive rig or something like that. So a lot of the pool work is very stressful. You’ve got to be mentally in the game to make it through those evolutions. The men are subjected to continual, calculated harassment by their instructors to see if they follow procedures taught in the classroom. Students are tumbled around and have their mouth pieces torn from their mouths, simulating the effects of a strong ocean surge. Students are taught two types of scuba. Open circuit, using compressed air bottles, and closed circuit, using specialized oxygen recirculation equipment. San Diego Bay turns into a combat training area for practicing underwater navigation. The men are learning to use a specialized breathing apparatus; the Dräger LAR V. It’s a closed circuit underwater breathing apparatus designed for clandestine military operations in shallow water, where concealment of telltale exhaust bubbles is essential. In a modern 50-foot dive tower on the BUDs compound, the men perform free swimming ascents without the use of a breathing apparatus. It’s all part of learning the specialized breathing techniques necessary to be a special warfare combat swimmer.