Yes airline would do a full refund if I bought the ticket at full price; here was the same case this person bought the place at full price it was not discounted by dive op. Also they can charge whatever $100 200 cancellation fees, but flatly refusing to return the money is not acceptable.
That means from now on each diver should also have a fine print form that he should get is signed by dive op that is they cancel the tour then on top of full refund dive op will have to pay penalty for causing us in convenience.
The ppl who sign up for the cruise are not just playing around, there has to be something serious that came up and have to cancel the plan, so being the customer does he have to take a hit, I dont think so.
Do think after this rescheduled trip this person is ever going to return to this OP I dont think so, if the OP would had returned his money I can guarantee 101% this diver would had returned to this OP whenever he was going back again on the trip.