The man pulled from the water near the Fish Eye Marine Park in Piti Saturday was a sailor.
He has been identified as Petty Officer 3rd Class Daniel Perez from California. He was a Naval Aircrewman with Helicopter Sea Combat Squadron 25. He was 22 years old.
An autopsy will have to be performed to determine whether he drowned or died from another cause.
Joint Region Marianas released the name of the sailor following notification of his next of kin.
According to a statement from JRM, Perez was snorkeling in the Piti Bomb Hole area in front of Fish Eye Marine Park when he was found unresponsive in the water.
Fellow seamen conducted CPR on him and contacted emergency services.
Guam fire medics transported Perez to the U.S. Naval Hospital where he was later declared deceased.