We have the Shimmering Lights Ariel. It does not swim by itself by my DD does regulalry use it in the tub. After being in the tub sometimes it does not work for a while and then it starts working again. It ususally works in the water but sometimes it gives out for a while. When she got it as a gift I wasn't sure if she sould be allowed to use it in the tub and I looked at the manufacturers website and it said in the description that it could...so we did! She loves the doll!