Sorry, our excursion was canceled due to vessel problems so I don't know much. We just walked around the port and did some shopping. I hear the snorkeling is amazing there but your 4 year old may not enjoy, mine never did. The family we sat with at dinner really enjoyed the snorkeling there and said it was amazing. My guess, a 7 and 4 year old would be OK just riding the tender back and forth. Haha.