The Leviathan 2 was built for Crown Zellerback as a high speed workboat in the late 80’s. Her shallow draft and speed tend to point to use as a riverboat (Fraser Watershed.) The lakes shown below are access to valleys that were full of high grade timber. The logs fed mills on the Fraser river. Also could have worked the Clayquot Sound area near Tofino.
Google was unable to find any photos. My guess would be a open back deck for cargo and seating for under 12 to avoid passenger rules. No wonder stability is a issue.