Dominic William O'Carroll was figured out missing after a crew member aboard the ship reported seeing a large object (person) go overboard Monday morning.
A passenger count was taken immediately and the Irish citizen, reportedly travelling alone, is believed to have gone overboard Horizon ship in the Caribbean Sea.
US Coast Guard and rescue crews assisting the operation have since called off sea search, 16 nautical miles of Puerto Rico’s Vieques.
According to Capt. Robert Warren, Sector San Juan commander, the circumstances surrounding the disappearance of that passenger remained unclear. William O'Carroll was last sighted by the security cameras in several spots aboard the ship prior to the accident.
Coast Guard rescue crews have conducted 12 air and surface searches since early Monday morning, covering an area of 1,265 sq. nautical miles, one third the size of Puerto Rico. A 110ft patrol boat, a 33ft Special Purpose Craft Law-Enforcement vessel, a Coast Guard Auxiliary aircraft, Civil Air Patrol and MH-65 Dolphin helicopters were all involved in the search.