I agree with Nick. I spent a few years working aboard tall ships; initially as a volunteer, then as a paid AB and finally as an officer.
It is indeed a very small, tight knit community once you break into the fraternity. I would suggest checking into the schooners that operate out of Key West as day boats. They have a busy winter season and pretty high turnover so they would be a good place to look this time of year. You won't get paid much, if anything at all. But a season on one of them will at least give you enough ammo to talk to the crews on the bigger boats about working as maintenance crew. Once you prove you're willing to work hard chipping paint in the snow it's pretty easy to step into a full time position.
Don't hold out for something with a topsail, get on any gaffer that will have you.