Ask Flowey 2!

Come on in, Four!

Chara: Hm? Oh, uh... They're just playing in the water! You can join them if you want! I... I can't actually swim, I've never been anywhere like this before, but... I can still take you in! *She goes into the water, until it's up to her waist* Come on! It's pretty fun!

*With Frisk*

Frisk: Hey, Six! Why aren't you in the water?