Here is an articale I found about auditions for cruise ships. It's short but ok...

Cruise Ship Dance Auditions
by Christina Gentle
Cruise ship dance auditions can offer new opportunities for dancers who are looking to get away from their crazy routines of constant auditions while juggling extra service industry jobs. Dancing on a cruise line can let you take a vacation for a couple of months, and get paid to work at the same time. How much do dancers make on cruise lines? Well, it depends. The average is anywhere from 300 to 700 a week, depending on the cruise line.
Dancers who make it past the final cut of Cruise Ship Dance Auditions are usually asked to sign a contract. The contract can be anywhere from two to six months. Dance employment on a cruise ship normally lasts in one to two month intervals with a month long break in between them. Dancers are often required to attend rehearsals during their breaks from sea travel.
To do well at cruise ship dance auditions, dancers should be well rounded and well trained. Cruise lines look for all types of dancers who are strong in ballet, tap, jazz and other forms of dance. Dancing on ships can be quiet different than dancing on land. For one thing, ships tend to rock and move around in the water. Dancers should be prepared for this.
Learning About Cruise Ship Dance Auditions
Cruise lines often advertise their audition information on dancer focused websites, in newspapers and artist magazines. Auditions can be held all over the world. You can research online to learn when a cruise line is auditioning in your area. There are usually a series of auditions and call backs before the final casts are chosen. One cruise ship can hire several different casts of performers in one year.