My guess, the major championship organizers have their own insurance and assume they will be sued regardless of whether the racers have insurance. They have covered their butt, and assume the racers should do the same but leave it up to them.

I will always argue for proof of insurance at our regattas. Two years ago we made it mandatory, and it did force a few sailors to get insurance the days before the regatta that did not have it. Then on Friday night a squall came through and tossed a number of boats. One of the owners whose brand new boat was tossed got insurance the day before, and yes he was really happy he got it.

I also think its a good idea to require skippers to have liability insurance in case they do run someone over coming to or leaving the beach. At our past ocean regattas I have seen several instances were a catsailor almost hit a swimmer while trying to navigate the surf. Sailors should have liability insurance for that slim chance that they accidentally hit someone. As an organizer, I think it partly your responsibility to make sure they have it.