I never try it in a Jacuzzi, but what I suggest is to place medical tape over the adhesive in a square like shape, that should hold it very well. I sweat alot and when I see the adhesive falling I place medical tape to support it and it do. Hope this helps!
Check this post!
I swim with my Dex (the sensor) on all the time and it is just fine. I think the only thing you may need to look out for is in hot water like in a hot tub. But even then, I'm not sure if that's a problem.
I went to a spa w/mine and had no problem in the hot tubs or after. Have fun!
I spent about 3 hours in the hot springs and thermal pool and the Blue Lagoon in Iceland, and my sensor was fine the whole time. No additional covering or adhesive. I got out once to check my blood sugar, and the receiver picked up a reading right away. I think the temperature was probably around 100 - 110 F. If you're keeping the sensor submerged for a while, a little bit of water may get in there, so it's probably a good idea to pop the transmitter out and just wipe off the contacts to make sure there's no lingering moisture, and then put it back in the sensor.
What about the bubbles and the water pressure!?
It should all be fine. The receiver is the piece you have to worry about.