Sad. Lemme guess. The boat was only certified to carry 4 people.
“A three-hour tour, a...”
One does not go missing in the water, one drowns.
“The sightseeing boat had been in the area of the Shiretoko Peninsula, in the northern part of Japan’s northernmost island and was believed to have been near the Kashinu Falls”
Without life rafts you are dead in that cold water from hypothermia even with a life vest. Cold water kills. The life vest makes it easy to find the body. I worked the North Sea and know. We had survival training to work on the oilfield drilling rigs in the North Sea. Go in the water even in the summer without a survival suit you are dead. In the summer with a survival you will probably make it. In the winter unless picked in just a few hours you are dead.
As the body chills it directs blood to vital organs and the brain. You loose the function of arms and legs. You just float in your life vest totally devoid of peripheral control of your limbs. You will probably die.
Maybe another US sub hit it....
A threeeee hour tour....