We just got off of the Spirit last Friday. It spent two days in Cabo and while the weather was nice, the water was 58. My grown daughter and niece took the snorkeling tour and the only people that stayed in the water had wet suits.
My niece stayed in for less than ten minutes and my daughter didn't even go in because they ran out of rental suits. They still had a great time due to the fun onboard the snorkel boat.