Since much of a SEAL's work is done underwater, SCUBA (self-contained underwater breathing apparatus) and combat swimming are top priorities for training.
SEALs train extensively for eight weeks in closed-circuit SCUBA systems and underwater navigation.
During land-warfare training, SEALs train for nine weeks in intelligence-gathering and structure penetration, long-range reconnaissance and patrolling, and close-quarters battle. They are also trained to react to sniper attacks and to use "edged" weapons such as knives and other blades. SEALs must be able to drive any vehicle and be skilled in high-speed and evasive driving techniques. Hand-to-hand combat is also taught during this phase of training.
To be prepared for anything, they are taught the tactics small units must use, including handling explosives, infiltrating enemy lines, recovery (snatch-and-grab) techniques, and proper handling of prisoners. SEALs must also be able to survive in extreme environments and provide medical treatment (field medicine).