smoke rises, so dont worry about anything underwater
I don't believe the code addresses this, but the terminals will corrode eventually. That's what testing and inspection is for. I would recommend to the customer that it all devices in the area be removed and inspected for corrosion. I don't know if this is code compliant, but, I have seen dielectric gel on terminals and WP wire nuts used in pool areas to slow down the corrosion.
I just moved (replaced) an FACP for a clubhouse/pool house. They were storing all the pool chlorine under the panel. The integrated DACT phone jack terminals are gold coated. Gold freely corrodes in the presence of chlorine I learned. It took 7 years for it to finally fail though.
I used all PVC conduit for relocation, and at the old FACP location has a 6x6x6 PVC JB and all the connectors are WP, as I do not want them to corrode.