The survival of three anglers who drifted in the pitch-black sea for nearly 11 hours was attributed to their life jackets and relatively warm water temperatures, authorities said.

According to the Incheon Coast Guard and other sources today (August 10), three men in their 20s and 30s, including a person identified as A, went out to sea for fishing aboard a 0.28-ton motorboat from Wangsan Beach in Yeongjong-gu, Incheon, at 12:30 PM yesterday (August 9).

Mr. A and his companions lost contact after their last phone call with Mr. A's wife at 7:10 PM yesterday.

Later, Mr. A's wife reported the situation to 112 at 10:30 PM the same day, prompting the Coast Guard to mobilize aircraft and patrol vessels for a search operation.

The Coast Guard located the group at 6:12 AM today, approximately 11 hours after they lost contact, in waters near Choji Island, Jawol-myeon, Ongjin-gun.

At the time of the rescue, the motorboat was capsized and mostly submerged. One of the men was perched on top of the boat, while the other two were holding onto it waiting for rescue, according to authorities.

All of them were wearing life jackets.

They showed symptoms of hypothermia upon rescue and were transferred to a hospital, but their lives were not in danger.

It was confirmed that their prolonged survival in the open sea was supported not only by the life jackets but also by the relatively warm water temperature.

The water temperature at the time was 25.8°C (78°F). According to the International Aeronautical and Maritime Search and Rescue (IAMSAR) Manual, when water temperatures range between 20°C and 30°C (68°F and 86°F), the estimated survival time for 50% of immersion victims is 24 hours.

This meant that had the rescue been delayed even slightly, the group could have faced worst-case scenarios due to hypothermia.

At the time, all of their mobile phones were turned off, and the motorboat lacked an Automatic Identification System (AIS), making it difficult to track their location.

In particular, limited nighttime visibility and the fact that the motorboat was nearly submerged made them extremely difficult to spot.

Based on the last known location provided by Mr. A's wife through a location-tracking application, the Coast Guard expanded its search area centering around Choji Island, leading to their discovery by a patrol vessel.

Believing the motorboat drifted with the currents, the Coast Guard is investigating the exact circumstances of the accident, including when the boat capsized, by questioning the survivors.

A Coast Guard official said, "Small motorboats are dangerous because they can easily capsize even from currents or wakes generated by nearby vessels," adding, "Anyone engaging in marine activities must wear a life jacket."

(Photo provided by Incheon Coast Guard, Yonhap News)