I can't really answer your question but do know that they will hire for a position that may not be listed.
My grandson went when they advertised, the position that he saw was in housekeeping. When he was interviewed and the person saw his training and work in culinary arts they told him they had positions on the Pride of America and started him on the hiring process. He is now working his second contract with them.
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Why not? I'm sure not everyone has done the type of job they were hired for. At least getting hired is getting your foot in the door so to speak. Then watch postings for upcoming opportunities. Or, as another posting said, there's likely "inside" info on jobs available or possibly potential openings.