Sean Mahoney |
The previous posters have hit the most Piratical Adventure Paths above.
Savage Tide has the disadvantage of being published in Dungeon Magazine so it is a bit harder to get a hold of. It also isn't really that you play pirates, but you do deal with them a fair amount, get your own ship and sail it to crazy places. It was also created for the 3.5 ruleset and so would need some conversion if you wanted to use it with the Pathfinder ruleset. There is a great community here though who might jump in and help or who may have already done the work... check it's message board area.
Skull & Shackles is very much a pirate themed adventure path (ostensibly), but hasn't been released yet... so I guess it is hard to find until it is. The good news is that it should start it's release soon.
Sean Mahoney