They are all cruise ships according to my last Captain. Agree it is different but so is a mega ship with 4000-5000 passengers. The size of
these limits what they can do in Australia and the islands. All have entertainment and activities. In Antarctica, on board we had lectures. A science lab, plus kayaking around small islands, sleeping out in the snow overnight, visits to international bases, and old ruins, even a shop and Post Office, plus visits to lots and lots of penguins!!