The code cannot, ever, be expected to specifically address every possible contingency. So, we have to look at the context of the code, as well as similar applications, and make our interpretations from there.
Secondly, this is a far from perfect world, and sometimes we just have to make do with something less than ideal. Again, only with the proper education, training, and experience can we attempt to "compensate."
First of all, the location: Let's see, just how "damp" is your hand likely to be, or your feet (while standing in the tub) when the switch is operated? Heck, if I could, I'd want such a switch to be not just 'damp' or 'wet' rated, but submersible!
Looking at a similar application -the part of the code that deals with pools and spas- we see that the code wants the lights themselves to be totally enclosed (weatherproof), as well as on a GFI. Not a bad idea here, either.
And not just a "GFI switch" either...I'd want the circuit feeding the switch GFI protected, with the GFI in another room, well out of reach.
Even if you could somehow guarantee that there would never, ever be a wet hand touching that switch, condensation will be drawn into that switch as a fly to a cowpie....best to have that switch totally sealed and gasketed as well. One of those outdoor covers with the lever comes to mind, or an industrial selector switch.
(FWIW, the latest such covers are raised about 1/4", and will accept a normal switch).
My preferred choice, though would be to MOVE THE SWITCH.
