Friendly. Easy to get bus into "town." Excursions were 1-2 hours bus ride away so we opted to skip. Montego Bay did not have scuba close by, so we hopped a bus and went to Doctors Cove to sun and snorkel. We spent a few hours there and then back to the ship.
Grand Cayman is easy walking distance to shops and restaurants once off the tender. We went scuba diving in Grand Cayman on our own because the one child was too young for the Carnival excursion. However, the dive shop we use is the same as the ship excursion. We have been at Don Fosters before and they set us up for a great two tank dive from the shore. We beat the crowd by walking over on our own. It was a great dive and we still got back to the ship for a late lunch!
In Cozumel we did go on the Carnival 2-tank certified scuba excursion and they were very good. Prompt and courteous. The dive master was very good with the two boys. Due to their age, they are limited in depth, but we could all dive in the same places and just keep the boys at the 40 foot level. Most of the diving is fairly shallow (60 feet or less). Beautiful!