Just cruised Carnival and dove with Dive With Martin. The 4 of us had a private boat that was waiting for us once we got off the boat. Getting off the boat is a chore, especially hauling gear for 4. DWM accommodated us with 2 dives and had us back in plenty of time for drinks and getting back to the ship with more than enough time to get to the balcony to watch the drunks come running as departure grew near. Email the operator of your choice and they will accommodate your needs. Lessons learned were:
1: more than likely, you will be diving with weight belts unless you bring your BCD's.
2: traveling with fins sucks...BCD's would be even worse
3: getting off a ship and worrying about a dive time departure may make you homocidal. 3000 people going out 1, maybe 2, doors and all thinking their schedule is more important than yours is not pretty. That's why we did the private boat for $10 more per person.
4. Dive 100 cu ft tanks, they did not charge me and it adds to your down time, especially at 60 feet.
5. We brought our own regulators, I did not want to trust rentals with our lives. We brought our own wetsuits and masks as well. My face is hard to fit and 99% of the masks out there leak like Niagra Falls.
6. Email the operator of your choice, all responded quickly and I asked some very direct questions regarding equipment. Only real issue was what they considered weight integrated BC's. Mine were non detachable Velcro pockets....
Have fun!!
Jay
BTW...we had about a block walk from the carnival pier...I think it's the International Pier...to the DWM shop. No big deal and no cab needed, even hauling gear for 4. Also, I researched Carnival's dive operator and did not use them. At the time it was Sand Dollar Sports. Horrible reviews from equipment issues/failures to safety while diving. Don't be afraid of the "if you don't use their operation, the boat will leave you if your late". Our last dive was within sight of the ship and there were lots of other operators around. We finished several hours before departure.