Sixteen people were still missing, more than 24 hours after the sightseeing vessel was lost off the coast of Hokkaido island.
TOKYO — At least 10 people who had been on a sightseeing boat that sank off the Japanese island of Hokkaido on Saturday have died, Japan’s coast guard said on Sunday. Sixteen other people were still missing.
The vessel had 24 passengers aboard when its two crew members sent a distress call on Saturday afternoon, saying the boat was taking on water. Another call came less than an hour after that, reporting that the vessel was now tilting by 30 degrees.
That was the last message from the Kazu 1, as the boat was called. On Sunday afternoon, after more than 24 hours of searching for survivors, the coast guard said 10 of the 26 missing people had been recovered, all of whom were later declared dead.
It was not immediately clear what had caused the disaster. But NHK, the Japanese public broadcaster, said there had been warnings of high winds and waves of up to 10 feet in the area of Kashuni Falls, a well-known sightseeing spot on Hokkaido’s Shiretoko Peninsula, where the boat had been when the first distress call was sent. Reefs are just below the surface of the waters there.
Naomichi Suzuki, the governor of Hokkaido, Japan’s northernmost island, said police officers and members of Japan’s Self-Defense Forces had been helping with the search, in waters colder than 40 degrees Fahrenheit.
Shiretoko Pleasure Cruiser, the company that owns the Kazu 1, said the boat left the port at Utoro, in eastern Hokkaido, at 10 a.m. on Saturday. It had been scheduled to travel around the tip of the Shiretoko Peninsula and return to Utoro around 1 p.m.
But somewhere en route, the 19-ton vessel, piloted by a 54-year-old captain with the assistance of a 27-year-old deck officer, ran into trouble and began to flood.
The coast guard sent five patrol vessels and two aircraft to the area. By the time they arrived, there was no sign of the boat or any of the people who had been aboard, said Tetsuo Saito, Japan’s minister of land, infrastructure, transport and tourism.
Early Sunday morning, three people were found at sea, all unresponsive, and taken by helicopter to a hospital in Utoro. Another unresponsive person was found on the rocks on the coast near Cape Shiretoko, and six more were found later on Sunday.
The Kazu 1 had run aground as recently as June, according to Tetsuya Umemoto, a spokesman for the Abashiri branch of the coast guard. None of the 21 passengers aboard then were hurt, but the coast guard investigated the incident and referred the captain to prosecutors, alleging negligence, Mr. Umemoto said. He said the deck officer at that time, Noriyuki Toyoda, was the captain on Saturday’s voyage.