Here is what I posted on the grog blog:
The same basic tactics that work in SVS work against the fleet. You can use those. In a perfect world it would break down like this. The Captain needs the following skills at max: Windcatcher, Tacking, Open Fire, Take Cover, and Leadership of course. The gunners need max lightining, and fury. The best ship depends on the size of ye crew. Big crew sail a War Frigate, small a War Sloop (my favorite). Then you sail circles around the fleet and pound them. Take out any Tyrant that dares to follow ye away from the fleet. As said above don't worry about stripping the sails, these ships stay mobile without them. Also don't bother to ram them either, Davy Jones and ye crew will be chatting if ye do!! Good luck!
To add to this don't hold still for more then a few seconds, this will get a complete broadside from the ship of the line. Also if ye be on a quiet server let the fleet get to an area with little or no other ships, that way they do not add to the problem.