Prior to commencing Basic Underwater Demolition/SEAl(BUD/S) training at the Naval Special Warfare Center, student undergoes 4-6 weeks of physical training and an indoctrination to BUD/s and the Naval Special Warfare community. BUD/S training is broken down into three phases.

The first, or basic conditioning phase, is nine weeks in length. Continued physical training in the areas of running, swimming, and calisthenics grow hareder as the weeks progress. Students will swim distances of up to two miles, participate in weekly two and three mile timed runs, tied obstacle courses, and learn small boat seamanship.

The sixth week of training is "Hell Week." During this week students participate in five days of continuous training. This week s designed as the ultimate test of the student's mental and physical motivation while in the first phase. during the remaining three weeks, the students learn the various methods of conducting hydrographic surveys and how to sketch a hydrographic chart.