There are many options.

First and foremost, if there is a lot of mist, even if you can see your subject, it will be difficult to get a good shot as your front element will be covered almost instantly. But, often, the mist is so prevalent, you may not even see your subject.

Unless you are after some sort of image in mind that includes extreme mist, I would actually stick to the basics:
  1. A good bag that either repels water naturally or has a rain cover
  2. A mist cover for your camera. I use ones from Rugged and Opteka. Just saw this review of the "Best Rain Covers for 2022."


As you mentioned underwater housing, maybe you are planning something much more intense than I had considered. For somewhat inexpensive underwater housing, you might want to consider this or other products from EW-Marine (granted, they are still pretty pricey).

Other than that, I would simply have a microlens cloth handy as you will be wiping down the front element often.

For whatever it is worth, playing with the mist and the lights that come on at night can make for great subjects.

Walk IMG_2645 by kayaker72, on Flickr

And then, fireworks + Falls.

Fireworks IMG_2254 by kayaker72, on Flickr