there may have been some people who got off in the last canoes  

THERE is the makings of a story.  They would have been adventuring into the (for them) unknown.  Say, a team of dolphin hunters out on the ocean thinks about what they are going back to, and what is bound to happen, how their catch is really not going to make any difference . . . and decide not to return . . . Brings to mind Kim Stanley Robinson's "Icehenge."  

The Fates are kind.