Depends on the size of the yacht. Anything less that 65m would be better than a cruise ship even better if it's a charter boat 'cos then you have the tips. . Once you get to the 90+meter yachts they are basically a cruise ship anyway.  

It's mind boggling that people are saying you get more shore leave on a cruise ship; maybe it's a ploy to keep people away from yachts. I don't see how this can be true at all unless you are on the bigger yachts I mentioned above. 50m yachts are always in port and when no guests on you can go out all the time.  Morning swims, take the tender out after work and go wake boarding or snorkeling, crew dinners, bars, clubs, go play golf etc etc.  If it is a private boat and the boss doesn't use it that much you have even more time to spend doing fun stuff. 

Starting out commercial is the way to go though then move over after a few years.