Activity/social/cruise staff would be your department to apply for, definately. If you in addition to your experience have a college degree, you are very qualified.
Cruise lines hire cruise staff from all over the world, so you being an aussie wouldn't make any difference. Any costs of Visa, medical etc you would probably have to carry yourself anyway.
Good luck on your process. It wouldn't hurt to follow up your applications like on any other job you're applying for.