I don't know the definitive answer to this but I bet they get around minimum wage and the issue o.t. because they house, feed and provide free medical care for the crew. Those things have to be taken into consideration when they determine salary.
There are all sorts of things that the cruiseline provides for the crew that mainland jobs do not.
Also, if you are in a position that earns tips, that is a whole other calculation. I think the minimum wage for that is just over $2-3.
(cruzin' solo by design)
Freedom ('09), Imagination ('08), Victory ('08), Destiny ('08), RCCL Navigator ('08), RCCL Majesty ('08), Glory ('07), Liberty ('07), Fantasy ('07), Destiny ('06), NCL PofAm ('05), Fascination ('04), Victory ('04), Fascination ('04), RCCL Voyager ('03), Fantasy ('99)