yes this is possible. but generally a pain in the arse. you have the choice of either private sailboats or comercial freighters. the best way to find transport on either is to live in a port town and actually go down to the docks or shipping offices and start asking questions. there are a couple of magazines printed that list job oppurtunities on private sailing vessels, cant remember any off the top my head. but, if you get serious and search the web you will find them. there is also one for commercial ships but these are generally very expensive, the companies who run regular routes with passangers charge alot of money. whereas if you contact a company or preferably a captain they are generally putting this money straight in there pocket and the price therefore becomes negotiable.
but, anyone can become an ABS (able body seaman) through the US coast gaurd, just get a physical and fill out the paper work and then you can walk into any commercial port and be hired on to work during your trip, granted you will be doing crap work, but you do get paid rather well.
hope that helps, probably not, but my advice is find some websites about deckhand jobs on private/ non-commercial ships and sign on, because its not about where you go but how you get there.