Blog Can You Use Condoms in Water?
Condoms are perfectly safe to use in water, whether in the shower or submerged (though I would suggest putting them on before you get in the shower, pool, ocean, submarine ... or whatever).
The bigger issue is that having sex in water can be a little tricky because the lubrication (whether natural or synthetic) tends to get rinsed away. If you don't have enough lubrication, the friction can wear down the condom and cause it to break. So what I would recommend is that you explore lubricants that are silicone-based. These lubricants do not rinse away easily from just water, yet are perfectly safe when used with latex.
Dr. Sandor Gardos