Hi, I did both those excursions last March and I brought my wallet with my money and sign and sale card along with a towel, sunscreen, underwater camera and bottle of water. They have lockers to use while at the park and they do take photos and videos of the swim for you to purchase. I took my camera and had one of the group members take a picture of me and the dolphin and purchased the video. Also in Grand Cayman I went with sotos cruises and took the same things even though I drank the lemonaide on the boat and purchased the video of the snorkel trip! I had no worries of my things being taken on either excursion. Have fun and don't worry.