According to the Coast Guard, they were discovered near Cape Shiretoko on the Japanese island of Hokkaido.
Four of the nine were found unconscious, according to the Coast Guard. The condition of the other five is unknown.
Authorities lost contact with the crew of the Kazu 1 boat on Saturday after the crew said water flooded the ship’s stern and it began to sink, Japanese public broadcaster NHK reported. The crew also said life jackets were on board and the vessel was listing at a 30-degree angle, NHK reported.
According to the channel, there were 24 passengers on board, including two children, and two crew members.
According to the Japan Meteorological Agency regional branch website, the sea water temperature in the area where the boat was believed to have sunk was between 35 and 37 degrees Fahrenheit (just under 3 degrees Celsius).
No one was immediately available for comment at the Japan Coast Guard after business hours.
The Coast Guard received contact with the ship around 13:15 (04:15 GMT) and dispatched five patrol boats and two aircraft to search, NHK reported. Local media reported that waves in the area were up to three meters (9.8 ft) high when the ship issued a distress signal.
No one answered calls to the office of the company that organizes tours of Kaz 1. According to its homepage, the ship has a capacity of 65 people. According to the tour company, tours of the Shiretoko area usually last about three hours.
The ship left the port of Utoro around 10 am on Saturday and was due to return to port by 1 pm, NHK said. The waves were high and fishing boats in the area were back in port by mid-morning.
The sightseeing boat was located in the Shiretoko Peninsula area, in the northern part of Japan’s northernmost island, and is believed to have been near Kashinu Falls, NHK reported.