My cruise of a life time was Galapagos Islands. We went last summer. We went with a tour group. It was 16 passengers in a boat, and we sailed around the islands for 7 nights. We were so close to the dolphins swimming next to the boat, they were getting us wet. One of the advantages of a small boat.
Anyways, we saw red, black, white (really white), and green sand beaches. And of coarse all the wonderful wildlife. IT WAS AMAZING!!!!