Antropometric measurements and Heath-Carter somatotype ratings were made on 32 subjects upon entry into a U.S. Navy underwriter demolition team training program. Twenty subjects successfully completed the 4-month program and were remeasured. Comparisons were made between initial and final scores for those completing training, and between initial scores for trainees who successfully completed the program and scores for those men who dropped from training, for the following variables: somatotype as a whole, three somatoptype components, height, weight, height/weight.33, sum of skinfolds, arm and calf girths, and bone breadths. No differences were seen between successful and unsuccessful trainees, on any variable, when results from the pre-training measurements were compared. Successful trainees did not change in height or bone breadths, but showed decreased skinfolds and height/weight.33, along with increased weight and girths. Successful trainees' somatotypes changed, with a decrease in endomorphy and ectomorphy, and an increase in mesomorphy.