I believe it is customary that you can belong to 'any' country's sailing associationg and sail in their sactioned races. What if people just joined another 'pro-catamaran' sailing association as a protest? (There was a time when I was member of USA, Slovenia, and Italian simultaniously)
You certainly can.
There's more: if you never officialy competed representing the US/USSailing, you can compete representing another country and its federation, if you follow their rules (residence in the country or something simmilar, usually).
Also, if you are affiliated to a foreign federation and compete in the US, US Sailing can not force you to pay them, otherwise your federation would (could) retaliate and do the same with US athletes competing in their races.
That said, many small central American and Caribbean countries would be happy to host US sailors. Not to mention Mexico, Canada, Cuba(!), etc.
