Basic Conditioning is when the going gets rough. This is the phase where most Drops on Request (DOR) happen. For eight weeks, trainees' days are filled with running, swimming, calisthenics, and learning small-boat operations. One-to-2 mile ocean swims and running the mother of all obstacle courses are daily, and timed, events. A trainee's time for these exercises must continuously improve.
Another important part of basic conditioning is drown-proofing. In this evolution, trainees must learn to swim with both their hands and their feet bound. To pass drown-proofing, trainees enter a 9-foot-deep pool and complete the following steps with their hands and feet tied:
- bob for 5 minutes
- float for 5 minutes
- swim 100 meters
- bob for 2 minutes
- do some forward and backward flips
- swim to the bottom of the pool and retrieve an object with their teeth
- return to the surface and bob five more times
Another evolution is surf torture, also called "cold water conditioning." The water temperatures usually hover around 65 degrees Fahrenheit (18 C), and never go above 68 degrees F (20 C). From there, trainees may be ordered to do some calisthenics or run a mile and a half down the beach in their wet clothes and boots. Then, they're ordered back into the surf. Many drills also require that teams carry their rubber boats over their heads as they run from one task to another.