You might get some ideas from this thread:
http://www.piratesonlineforums.com/forums/showthread.php?t=7350
To build on what HanMaster said. if you can get a friend or guild member who has thunderbolt to come along he or she can try to take out the sails while trying to do minimal hull damage (easier said then done). then the captain can place the ship out of harms way and you can blast away with chain shot or round shot to get max points. Once you get lightening that will help a lot, you'll be able to do this without depending on others.
I would also suggest that you put what points you can in to shoot and rapid reload so you can get as many shots in as you can when your with a crew.