Hm re Vortex Optics - is it size 24 or 26? As there seems to be two quoted.
I have drilled the original cap on the side, then put a thin bungee through but this would be a neater solution
You want the O-24 one.
I bought the Vortex and the Monstrum one at the same time. I felt like the Vortex one is better made and specifically says it uses a stainless spring, so I installed that one and ended up giving the Monstrum one away to a Meg diver... LOL
My first Vortex was recently almost 2 years old and I noticed the rubber boot was starting to get a split in it. The hinge spring was still totally fine, as far as I could tell. The Vortex one is really made for a scope that is just slightly smaller than the NERD. But, the boot is rubber and it does work very well on the NERD.
I ordered another one and have that on now. $20 every couple of years to protect my NERD is okay with me. I had not removed the original until I got the replacement. I probably should have taken it off occasionally to rinse under it, but I never did. My NERD still looks like new underneath where the cover was.
@jvogt The #1 most common repair that Dive-tronix does on NERDs is screen replacement after it gets left pointing at the sun and the lens focuses the sunlight on the screen inside. I have left my loop flipped up and over when my unit was on a boat and more than once had it get jostled (by a person? boat rocking?) so it ended up flipped back to the front where the NERD is "looking up". The cover is cheap insurance, to me. And, as noted, when the hinge is oriented properly, the cover does not noticeably impair my view.
Honestly, @Shearwater should get something like this made for the NERD and include that instead of the little cap that (almost) everybody loses.
