Not sure how your mobile is getting wet unless you are running through really deep water with doors off. If that is your normal use, then just get a commercial radio. Used ones are under $200 easily and do 50w. You might even look into used military gear. I have less familiarity with them but I know there are VHF sets out there folks use.
Otherwise, most any mobile you buy is fine.
For HTs, the Yaesu HTs are often sealed good. I think the VX7r I have is. That also poses a problem in that the microphone and speaker can be less than ideal because of the waterproof membrane covering them. Again, look at used commercial stuff here too. Figure if the fire service uses it, it has to be water resistant at the least.