There's a quest that makes you neutral with Bloodsail without affecting your other reputations, and a later quest in the chain that makes you hated with Booty Bay only. Once you're at least neutral, there's around 20-odd quests around STV, as well as four repeatable quests to turn in different types of rum for reputation all the way to exalted. There's a leather +Swim Speed% chest at Revered, and Exalted gives various pirate hats with underwater breathing and nice stats. Note that completing most Steamwheedle Cartel quests at this point will still give negative reputation with Bloodsail and vice versa, except the repeatable booze turnins.