I have been approached many times, by several cruise lines. All they offered was free room and board, in the crew area, which is not too nice (and it's not free, there's taxes and fees you have to pay, plus you have to get to wherever the cruise leaves from). I told them I make $1000 a day, and I'd be willing to barter. What that meant, was that provided I got a nice, outside stateroom, and first class accomodations for me and my wife, I would do the teaching. I can tell you that there isn't much teaching. Perhaps an hour a day, and it's a group thing...not much in the way of learning more than how to hold the cue, and stand. They declined to negotiate (saying that they don't pay their entertainers), and I've never gone.
Scott Lee
www.poolknowledge.com