All that may be, but we were on Octantis from 9 March to 7 May. There were limited sub ops in Antarctic waters and at two locations in the Caribbean. None from there to Milwaukee and the reason given was the challenge of compliance with regulations.
Given our experience, I would not recommend booking an expedition cruise because you must go in a submersible. The operating envelope is so small, the opportunity so limited and you will miss other events while waiting for your turn to dive. One couple was scheduled four times and never left the ship. My wife, once and missed an outstanding snorkel excursion.