Footage on NHK shows one of the rescued people arriving by helicopter and being transferred to an ambulance on a stretcher, while rescuers hold up blue plastic shields for privacy.
The boat with 24 passengers and two crew members was missing after an emergency call was sent Saturday, stating that the water was rising and beginning to sink.
Sunday’s rescue came after nearly 19 hours of intense searching involving six patrol boats, several aircraft and divers. The Coast Guard said the search continued through the night.
The 19-tonne Kazu 1 made a distress call early in the afternoon, saying the ship’s bow had flooded and began to sink and overturn while traveling off the west coast of the Shiretoko Peninsula near the northern island of Hokkaido, the Coast Guard said.
The tour boat has since lost contact, the coast guard said. It said the boat was carrying 24 passengers, including two children, and two crew members.
The average sea temperature in April in Shiretoko National Park is just above freezing.
An official for the ship’s operator, Shiretoko Pleasure Cruise, said he was unable to comment as he had to respond to calls from concerned families of the passengers.
Prime Minister Fumio Kishida, who attended a two-day summit in southern Japan’s Kumamoto, canceled his program for the second day and returned to Tokyo. He told reporters in the early hours of Sunday that he had instructed officials “to do everything they can for the rescue”.
The cause of the accident is still under investigation, but experts suspect that the boat ran aground and was damaged.
High waves and strong winds were observed in the area around noon, according to a local fishing cooperative. According to Japanese media, the fishing boats were back in port before noon due to bad weather.
NHK said there was a warning for high waves up to 3 meters (9 feet).
A tour boat crew from another operator told NHK he warned of rough seas when he saw the Kazu 1 crew and told them not to go. He also said the same boat ran aground last year and suffered a crack in the bow.
Yoshihiko Yamada, a marine science professor at Tokai University, said the boat likely ran aground after being tossed around in high waves and damaged, flooded and likely sunk. A tour boat of that size usually doesn’t have a lifeboat on board, and passengers may not have been able to escape a fast-sinking ship with the windows probably closed to protect them from high winds.
In an interview with TBS elevision, Yamada said there was also a small chance that the boat would have been hit by a whale.
According to Jun Abe, vice president of the Society of Water Rescue and Survival Research, the cold temperature and strong winds can cause hypothermia and put passengers in dire conditions for survival. “It’s a very serious condition, especially when they’re wet,” Abe told TBS.
According to the operator’s website, the tour lasts approximately three hours and offers scenic views of the west coast of the peninsula and possible sightings of animals such as whales, dolphins, and brown bears. The national park is a UNESCO World Heritage Site and is known as the southernmost region where the floating sea ice can be seen.