I have seen a few stuck gauges. My favorite example was in the Bahamas. I had only made something like 4 dives in the previous 2-3 years, and only had maybe 50 dives total at that point. I knew that my skills would be rusty and my air consumption poor.
For the third dive of the day we were going to do a “deep” reef (80’) because of the surface conditions. The dive master said we would all stay together as a group and come up as a group. I was looking around the boat and caught the eye of a couple of other people doing the same. We all had the same thought: I don’t want to be the one that drags the entire group out of the water! I even said out loud at that point: “I don’t have to be the best on air, I just have to be second worst!“
My instabuddy was grumbling under his breath...
Anyway, at the end of the dive, as I was getting low on gas, I signaled to my buddy that I needed to go up. He gave me an OK, but then kept swimming around the reef. After about 60 seconds, I grabbed his fin, showed him my gauge, and made a forceful thumbs up sign, turned around and swim to the anchorline about 10 feet away. When I got to the line I turned around to look for him, but he was nowhere to be found, so I went up the line as normal, did a safety stop, and went on board. Where my buddy was already on the boat!
Turns out that as I turned around to go to the anchorline he felt his regulator get hard to breathe. As I was swimming away from him along the bottom, he decided not to chase me but to start to bolt up towards the surface. He ended up meeting up with another group above me who was doing their safety stop, where they buddy breathed and made it to the surface.
On the boat, his gauge clearly said 1000 PSI. We took his reg off the tank and opened the tank: it was at atmospheric pressure!
The two things I like the most about that are: 1) I clearly did better on gas consumption that he did, because I made it back to the boat with gas to spare, and 2) how long did his gauge read 1000 PSI without changing and he thought that that was perfectly normal?
Ever since then, I’ve always paid attention to how far the needle has moved between glances, and asking myself if that how far I expected it to move during that time. That skill is worth a little bit of effort: it helps you to make sure that equitment is working as you expect, and it gives you an indication of circumstances where you might be working harder than you think. Maybe there’s more current than you feel, or you’re more keyed up then you might normally be. Paying attention to that can really help you to avoid issues well in advance of them becoming a problem.