I’ve been wanting a simple, reliable cover for my CMC‑2 on the Nauticam flip adapter—something I can keep on during entries/exits to protect the lens, and then remove and stash easily once I’m underwater.

Since I don’t have a 3D printer (or the CAD skills to design a custom cap), I decided to improvise. With a little help from Google Gemini, this is what I came up with.

The cover is made from a 70 mm vinyl end cap, trimmed down so the depth matches the CMC‑2. Inside, I wove bungee to create four small “tabs” that snap under the top ledge of the lens body. That gives the cap a positive grip instead of relying on friction alone. I also added a parking loop on the hinge—just an extra layer of security in case the cover pops off before I have a chance to clip it to a D‑ring at the start of the dive.

Any thoughts or suggestions for improvement are welcome.

By the way, there is a small hole at the middle of that cap to allow air to vent.

Edited April 29Apr 29 by Adrian Gresores