141021-F-FN000-153
Johnnie Yellock, left, retired Staff Sgt. and 23rd Special Tactics Squadron combat controller, attempts vertical swimming while Michael Gray, right, 24th Special Operations Wing water operations instructor, looks on during SCUBA-Pool Emergency Procedures training on Hurlburt Field, Fla. Oct. 21, 2014. One of challenges Yellock had during the refresher training was maintaining his balance in water without the usual support and propulsion of his legs.(U.S. Air Force photo/Senior Airman Kentavist P. Brackin)