Members of 3rd Reconnaissance Battalion carry a rubber inflatable raft into the water at Camp Schwab, Okinawa, Nov. 25, 2016. (Kathy Nunez/U.S. Marine Corps)

Three U.S. Marines out for a swim Friday night spent more than an hour adrift off Okinawa’s northern coast before being rescued, according to the service and Japan’s coast guard.

The trio and another Marine were swimming for about an hour near Henoko fishing port when the fourth Marine reported the others missing to the Marine Corps at 7:27 p.m., according to a coast guard news release Friday.

Boat teams with the 3rd Reconnaissance Battalion at nearby Camp Schwab were dispatched to find the swimmers, who are assigned to the 3rd Marine Division, division spokesman 1st Lt. Joshua Figueredo said by email Tuesday.

They were found uninjured at 8:53 p.m. about a mile southeast of the port, according to a map released by the coast guard.

Weather conditions were cloudy, with 11 mph wind gusts and 3-foot waves, according to the release. The sun had set 1 ½ hours previously.

One Marine was found on a rocky islet in the middle of the water; the others were picked up in open water, a coast guard spokesman said by phone Tuesday. None were wearing life jackets, he added. Some Japanese government officials may speak to the press only on condition of anonymity.

The Marines were assessed on the beach and taken to Naval Hospital Okinawa “out of precaution,” Figueredo said. The incident is under investigation.