KEY LARGO, FL - APRIL 7:  Jeremy Stengel, a  22-year-old U.S. Marine who lost his left leg during combat duty in Iraq 14 months ago, fits a special prostheses for his first try at scuba diving April 7, 2008 in the Florida Keys National Marine Sanctuary off Key Largo, Florida. The prosthesis features a foot that can be extended so a dive fin can be used as normal. Getty Images logo Getty Images 19 months ago

KEY LARGO, FL - APRIL 7: Jeremy Stengel, a 22-year-old U.S. Marine who lost his left leg during combat duty in Iraq 14 months ago, fits a special prostheses for his first try at scuba diving April 7, 2008 in the Florida Keys National Marine Sanctuary off Key Largo, Florida. The prosthesis features a foot that can be extended so a dive fin can be used as normal.