Ahoy, Nancy!
Thank you for sending in your splashtacular question to the Disney Parks Moms Panel! The pools onboard are heated once the outside temperature drops below 75 degrees, so I would certainly bring bathing suits on your Alaskan sailing. My kids swam on our Alaska cruise two years ago so the cooler temperatures did not bother them at all as well as many other Guests onboard. In fact, our last sea day ended up being 80 degrees without a cloud in the sky so you never know what you'll encounter in the Last Frontier! You really want to be prepared for every type of weather situation.
You'll also be happy to know that complimentary flotation vests in various sizes are available on the pool deck. Since space is probably going to be tight with the variety of clothing you'll need to bring, I would plan on borrowing a vest provided by Disney Cruise Line for your sailors. They are made of closed-cell foam and coated with vinyl so they are very lightweight and comfortable to wear.
Nancy, the next few weeks will fly by so try to prepare a little each day for your
Alaskan adventure on the
Disney Wonder. Layering and an outer waterproof layer is key to being comfortable when heading ashore to explore! I also highly recommend waterproof shoes as well. You'll be so glad to have them if you encounter any rain.
Please let us know if you have any other last minute questions! If not, have an amazing time!
Nancy