 Calling the seizure " piracy " , President Ford ordered a military response to retake the ship and its 39 @-@ man crew , mistakenly thought to be on Koh Tang Island . On May 13 , two A @-@ <unk> <unk> saw the 39 man crew board a fishing boat and saw people disembarking fishing boats at Koh Tang Island . They assumed that the Mayaguez crew was on the island . Elements of the 1st Battalion , 4th Marines , the 2nd Battalion , 4th Marines , and the 2nd Battalion , 9th Marines , were flown to an advanced staging of a joint US Task Force . On May 14 , the Marines from Company D , 1st Battalion , 4th Marines boarded the Mayaguez only to find it deserted and raised the American flag . A Thai fishing boat with a Thai crew and the 39 crew members of the SS Mayaguez which had been set free , approached the USS Wilson . 
