Whole family is going on NJ to Bermuda cruise this August, for my dad's 70th birthday. Three kids - ages 3, 2.5, and 1. I've been put in charge of coming up with the "birthday activity" while on the trip. I need help planning this - I've never been on a cruise, and I don't have much experience planning these kinds of things. Any ideas? Should it just be a birthday lunch on the ship, or perhaps something onshore? TIA.