Obstacle Course (O-Course)
The obstacle course, known at BUD/S as the O-course, is the timed route candidates run repeatedly against set standards. It appears in the orientation course, in Second Phase's course content, and among the graded events of First Phase.
Where It Shows Up
MILPERSMAN 1306-1016 (10 December 2024) names an obstacle course twice: once in the orientation course's conditioning programme, and once in the Second Phase's course content, alongside open-circuit and closed-circuit diving, distance running and aquatics. In First Phase it is one of the timed events. The 2023 command investigation lists the swims, the runs and the obstacle course together as the evolutions with set standards that a candidate has to meet before Hell Week.
The Standard Is the Standard
Failing one of those graded evolutions before Hell Week is an automatic drop approved by the commanding officer rather than a case argued to a board, which is why the course is run against a clock rather than judged on effort. The class also gets daily verbal or written feedback, and a candidate trending below average is pulled from training for review. The course is one input into that record, and it is one a candidate can rehearse.
Training Without One
Most candidates have no obstacle course near them, and they do not need one. The course asks for the same three things as the rest of First Phase: the ability to run hard on sand, the upper body to get up and over, and enough grip and shoulder endurance to hold on. Strides and sand runs cover the first, pull-ups and presses the second, and hangs and carries the third. A candidate with a park and a pull-up bar can build all three.
Practise obstacle work once fresh, then again tired. Times are set on a day when you have already run, swum and done a few hundred repetitions.
Related Terms
First Phase is the seven-week opening block of BUD/S, the phase that selects and prepares candidates physically and psychologically for the rest of the pipeline. It holds Hell Week, and it is where most of a BUD/S class is lost.
BUD/S orientation, which the Navy calls Naval Special Warfare Orientation (NSWO), is the seven-week course candidates complete before BUD/S begins. The Navy describes its purpose as building the conditioning base and the water competency that the pipeline then demands.
Upper body strength training in the NSW preparation program targets the major pulling and pushing muscle groups through compound barbell and dumbbell exercises. These sessions complement the calisthenics work (push-ups, pull-ups) by building the raw strength that supports higher-rep endurance performance.
The 1.5-mile run is the final event of the Physical Screening Test (PST) and measures a candidate's running speed and cardiovascular endurance. Performed after the swim and calisthenics events, it tests the ability to produce a fast run effort on fatigued legs, a skill directly relevant to BUD/S demands.
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