This is a photo of the Leviathan II in better days:
https://shawglobalnews.files.wordpress.com/2015/10/dsc_5239.jpg?quality=70&strip=all&w=1200&h=800&crop=1

It's a large enough boat that people normally wouldn't wear life jackets but would be made aware of their location, should they be needed. The sudden and unexpected rolling of the boat, when hit on the side by a large wave, cast passengers into the sea without time to look for a flotation device. The fact that most of the passengers survived is largely due to the quick and caring response of people from the Ahousaht First Nation.