Hi Stephanie!
Welcome to the Disney Parks Moms Panel, and congratulations on booking your first Disney Cruise! We cruised with our kids at the same ages, and it was a blast. They're in for an awesome voyage with Captain Mickey!
I've checked out the Port Adventures in Key West that are available to you. If it's a water adventure you're looking for, your best choice would probably be to stay onboard and enjoy the lighter crowds at the pools and water features. There are several adventures available in Key West for kids under the age of 5 - most are sightseeing tours. I encourage you to check out the Port Adventures
here to see if there's one you think your kids would enjoy! (You can search by age on the left side of the page to see which ones are approved for children 5 and under.)
If you choose to stay onboard, you won't have to look far for fun. Character meet-and-greets, pool games, and first-run movies are just a few of the ways you can stay entertained during a day in port. Each day, you'll have a Personal Navigator delivered to your stateroom - a detailed schedule of all the fun activities happening on the ship. My family likes to bring colored highlighters so we can each make notes of our "can't miss" activities!
Make sure to check out the
Oceaneer Club/Lab on your first afternoon on the ship - your kids have a world of fun available to them throughout your cruise. Youth counselors provide excellent care for the littlest cruisers while entertaining them with games, art activities, and more. There's always something fun going on in the Youth Clubs!
I hope this helps. Please come back and visit if you have more questions as you make your plans!
- Diane W.