BUDS trainees go through DROWN PROOFING. It is a technique where the trainees hands are tied behind their backs and feet are tied together. The trainees are tossed into the combat swimmer tank and have to learn to stay calm and perform various tasks, like recovering a dive mask from the pool bottom with their teeth. They must continue to stay in the water until the instructor staff is satisfied. There are various methods that trainees use to complete this evolution. If this training evolution is not completed successfully, the trainee is dropped from training and will not complete SEAL training.
Addendum: (So, not intentionally...)
Holding you're breath is something that is not taught it is just done. The SEALs train their minds by doing underwater swims and drown proofing.
Before, then U.S. Navy Seals, were who they are, they were classified UDT - or - Underwater Demolition Team. I don't know when they officially became Seals. JFK authorized the formation of the SEALS.
Navy seals all the way dude,
There is not a way to pin point missions done by Navy Seals. The Navy Seals go on many of missions.
The motto of United States Navy SEALs is 'It Pays to be a Winner'.
Navy seals do.
Navy Seals
navy seals win
Navy seals are "frogmen" in that they conduct amphibious operations.
The US Navy SEALS is a Special Operations Group of the US Navy
The full form of Navy SEALs is "Sea, Air, and Land Teams."
None. Navy Seals are all Navy. Marines are a completely different branch of military.