As I just explained, the referral required has nothing to do with insurance. It is a completely separate process. Source- work in medicine at a major Boston hospital

No. Many specialists now require a “referral” (not an insurance referral) from another physician which they then evaluate to see whether they will see you or not. It depends on many factors but if they dont feel that the referral is appropriate or they dont want to deal with your issue that can refuse to see you. Again it has zero to do with insurance. There are many more patients than drs available to see them which is why there are such long wait times.

Its quite cool there in April so it wont be beach/pool weather there and of course on the way there you wont be hanging out on the deck and swimming. That would put me off doing a cruise.