It's fine. Just don't start humming the theme from Jaws or anything.

[She paused, treading water herself, so low in the water only her nose and eyes were visible. Then she lifted her chin to talk.]

Hey. Race you to the far shore and back?

[This would be a pretty long round trip, and would take them closer to the cabins than would strictly be safe for purposes of non-discovery. Yes, she was aware of all that.]