According to Fitbit, your Ionic is Water resistant enough to swim in a pool with
In fact there is an swim recording mode for the watch for this.
There is no legal definition for the term waterproof.
Can I swim or shower with my Fitbit device?
You can swim with Flex 2, Ionic, and Versa and shower with Ace. Do not swim or shower with other Fitbit devices
How do I use exercise apps and modes on my Fitbit device?Track specific exercises and save the data to your exercise history
You should have already downloaded the
Versa Product Manual