Underwater night vision is very doable. Here is an article with a photo taken by one of our low level light digital cameras -
https://ilphotonics.com/photoniss-underwater-imaging-for-sustainable-aquaculture/. An actual night vision goggle also works well, with the caveat that "works" is environmentally dependent upon the factors present when your NODS are on underwater - in other words the amount of light available. At 20 meters there is plenty of light available (unless you're diving at night). If you're working deep or at night you can use supplemental lighting to assist, and you don't need a bright white light. A 350nm blue light will provide enough for the NOD to detect and amplify (for a Photonis tube). The photo in the article was taken at 231 feet (70m) with a Nocturn low level light digital camera with very low level additional lighting. We also have the iNocturn which is a Photonis 4G image intensifier tube mated to a CMOS. That one performs even better, and the best we have is our Ultimate Digital Night Vision Camera which we developed for the US military which is a true digital night vision camera with the same performance as an analog image intensifier tube equipped NOD (because it has an attached image intensifier tube).