Taken by surprise as it docked in Aden Port, the explosion alongside USS Cole tore a 40 by 20 foot hole along the waterline killing at least six American sailors and leaving 12 missing. Authorities said a small boat assisting in mooring the ship in Yemen on the Arabian Peninsula staged the attack. But more than a mere surprise, the attack seems to have taken advantage of inherent weaknesses in security at the port. U.S. vessels have visited for several years, but have only gotten fuel about a dozen times in the last year. This would allow terrorists plenty of opportunity to observe refueling and take advantage of weak security. The USS Cole had implemented terrorist countermeasures, according to Navy protocol. Every U.S. ship follows a predetermined force protection plan for every port visit.