Cayla,
Thanks for asking your question to planDisney!
Absolutely, yes you can swim with your 
MagicBand+! 
My family and I were just at Walt Disney World for Spring Break, and we loved not having to worry about our bands as we dove into the pools at 
Disney's Contemporary Resort. It is also reassuring to know that the bands are waterproof for pools and water rides when you are floating down the lazy river at 
Disney's Typhoon Lagoon Water Park, or rafting the 
Kali River Rapids in 
Disney's Animal Kingdom Theme Park!  
BONUS TIP #1The original version MagicBand is also waterproof for pools and water rides. 
BONUS TIP #2I would strongly recommend you get a MagicBand+ for each person in your party. Some of the interactive features can be a lot of fun like using them to participate in the 
Batuu Bounty Hunters quest in 
Disney's Hollywood Studios. All the other features, like keyless room entry, charging capabilities, and ticket media access, also are wonderful conveniences.
BONUS TIP #3Pairing your new MagicBand+ to your account could not be easier. Just make sure you have the 
My Disney Experience App installed on your smartphone, and you will see it offers some simple steps on how to pair the band to your account, as well as how to personalize your settings. 
Please feel free to 
write me back directly if you have any follow-up questions.
Have a Magical Vacation!
Doug