Women and Marriage
Use your charm and charisma to win over the favor of townswomen. When you visit the town again, they will freely give you information that is otherwise hard to come by. Be content to just "Make Conversation" with perspective brides until you have gained considerable rank and reputation. Then marry into the governor's family.

Keep the Crew Happy
Sailors are happiest when their share of the loot is more than a pittance. Therefore, before divvying the spoils, sacrifice part of your crew in battle. This will significantly increase each man's share.
(Note: Don't slaughter all of your men or you may find yourself captured.)

Seize control of Seafaring Vessels
The easiest way to seize control of a seafaring vessel (particularly when you are out-gunned and out-manned) is to climb aboard and fight the captain on her deck.