My daughters were both 5 when they started snorkeling. Have your kids done it before? The girls went to a diving shop that gave snorkeling lessons. It was only for a couple hours, and they have loved it ever since. Where are you going on your cruise? In some places they had a hard time with the current and were tossed into coral but so did my husband. Have a wonderful time and I know the kids will. As for the club, my kids never wanted to leave.