Two so far - one I'd call an emergency and the second an almost-emergency? And a situation that could've become serious but was addressed early on. All three are equipment related in some way.
1. Out of Air - my dive buddy - he ran out while we were photographing sharks. He didn't want to panic me and I wasn't the closest diver to him so he was assisted by another diver and I didn't know what had happened until after the fact - Apparently he actually ran out during his safety stop and his gauge showed 500psi even when he was out. Testing on the boat showed his tank really was pretty much empty (stuck another reg set on it to see what it read).
2. Stuck inflator button - gear issue - victim and problem solver. I had noticed my buoyancy was a bit off for a couple dives but assumed it was a weighting issue as I had just switched to a thinner wetsuit and assumed I hadn't adjusted my weighting properly - earlier in the trip I'd had no problem achieving neutral buoyancy with little/no air in the BCD but suddenly I kept having too much air and I kept needing to vent it out. I assumed it was operator error until we were on a 100ish foot wall dive with a fun but mild current and the bcd started rapidly inflating. I popped the hose off the inflator and vented all the excess before I'd risen more than 10 feet.
Once I was back to neutral, I pointed it out to my buddy in case I needed assistance later, and proceeded to have a great dive. I even have photos from that dive where the hose is detached.
Oh maybe 3.
We were doing a lake dive in an area with heavy boat traffic so were towing a dive buoy thing on a line. The guy towing it wasn't paying attention and got it tangled around his tanks and valve and somehow around a dock and another line (idk what it was for but it was more a steel cable). He didn't notice and didn't seem aware of where the line was. I was back a bit and saw so got his attention, got him and my buddy to stop (yay three diver group), and quickly untangled him and pointed out the area above where it was getting caught. No emergency happened but it easily could've become bad.
1. Out of Air - my dive buddy - he ran out while we were photographing sharks. He didn't want to panic me and I wasn't the closest diver to him so he was assisted by another diver and I didn't know what had happened until after the fact - Apparently he actually ran out during his safety stop and his gauge showed 500psi even when he was out. Testing on the boat showed his tank really was pretty much empty (stuck another reg set on it to see what it read).
2. Stuck inflator button - gear issue - victim and problem solver. I had noticed my buoyancy was a bit off for a couple dives but assumed it was a weighting issue as I had just switched to a thinner wetsuit and assumed I hadn't adjusted my weighting properly - earlier in the trip I'd had no problem achieving neutral buoyancy with little/no air in the BCD but suddenly I kept having too much air and I kept needing to vent it out. I assumed it was operator error until we were on a 100ish foot wall dive with a fun but mild current and the bcd started rapidly inflating. I popped the hose off the inflator and vented all the excess before I'd risen more than 10 feet.
Once I was back to neutral, I pointed it out to my buddy in case I needed assistance later, and proceeded to have a great dive. I even have photos from that dive where the hose is detached.
Oh maybe 3.
We were doing a lake dive in an area with heavy boat traffic so were towing a dive buoy thing on a line. The guy towing it wasn't paying attention and got it tangled around his tanks and valve and somehow around a dock and another line (idk what it was for but it was more a steel cable). He didn't notice and didn't seem aware of where the line was. I was back a bit and saw so got his attention, got him and my buddy to stop (yay three diver group), and quickly untangled him and pointed out the area above where it was getting caught. No emergency happened but it easily could've become bad.