I have used the "Hydrotac" and the wider Trident Dive Optx and I find the Trident Dive Optx to be much better for diving because they are wider. I almost always lose one that comes off from the mask and learned to install just one on the left side and use the other one as spare. You need to make sure that it is all on and doesn't show any part coming off, if it does, you need to reinstall it. You have to leave it for about 48 hours to dry before using it after installing it. You have to make sure that it is installed at the right high on the mask glass, not too high where it become annoying and in the way or too low where you have to strain your eyes trying to look down too low down to be able to see the gauges.