Very few Americans work on cruise ships in any field except cruise staff. The work is too hard, the hours too long and the pay too low. If you don't apply as a couple you're not likely to even end up on the same ship. Also, lines require that you sign contracts for x amount of time, so you may not be able to just work the few months that you want. I'm not saying don't go to work for a cruiseline, but don't expect it to be on your terms.