Is this because the keys are not physically accessible? If so, it's possible you could use a Canon Basic script, though it would likely be awkward.
So it's not absolutely impossible but definitely not manageable under water. The problem is that the camera has no wheel and is mainly operated via touch. This is not possible in the underwater housing. I can only use the front ring and the zoom slider. Since the whole thing goes through a gearbox, it is extremely difficult. The zoom slider does not work in every menu either. Also starting the script is not that easy in the underwater housing.
I was hoping I could set the underwater white balance with a script and then save it under C.
