A U.S. Marine with Marine Corps Air Ground Combat Center swims through an amphibious obstacle course at Twentynine Palms, Calif., Oct. 8, 2014. U.S., Dutch and British marines competed in the Combat Center?s High Intensity Tactical Training Black Alligato

- Image ID: E9TYR8
A U.S. Marine with Marine Corps Air Ground Combat Center swims through an amphibious obstacle course at Twentynine Palms, Calif., Oct. 8, 2014. U.S., Dutch and British marines competed in the Combat Center?s High Intensity Tactical Training Black Alligato
501 collection / Alamy Stock Photo
Image ID: E9TYR8
A U.S. Marine with Marine Corps Air Ground Combat Center swims through an amphibious obstacle course at Twentynine Palms, Calif., Oct. 8, 2014. U.S., Dutch and British marines competed in the Combat Center?s High Intensity Tactical Training Black Alligator Challenge.