How do i find a job in the maritime industry? (Deckhand work, and such)?

It's been a dream of mine as far back as i can possibly remember to work on a Boat/Barge/Ship, doing deckhand work... I was just wondering, where and how do i go about finding such work? Craigslist, and places like that don't seem to have anything close to what i'm looking for... I live in Savannah GA, if that helps at all.