here in AUS i know our club got an cheaper insurance premium for public liability, rsq craft, and on water insurance if all the privately owned (racing/cruising) boats where self insured. To the point i had to show my papers when i signed up for the season.I also heard that a few years ago now that some officals here got sued personally for an event, so from there on we all have had to show insurance papers.
On a personal thing I always sail my boat as if now other bastard is insured out there, because i have ugly things on the beach afterwards between people , its just safer that way i know that ill probably never win but then ill never have boat repairs etc