Good call & desciption! No critics or suggestions, just want to share my 1st thumb-up experience. This happened after a bad experience of barotrauma.
The barotrauma incident
I normally equalize my ears continuously, every 1m descending for the 1st 15-20' by pinching my nose with my left fingers, while holding my camera with my right hand. One day in one of dive site in Bunaken, we hit an up-current that forced us to do a negative entry from the surface to the ledge of dive site wall. I didn't make any progress descending as I swam against the up-current. The lead DM then turned around and looked up and saw that I was struggling near the surface, trying to descend. He went up & grabbed my left arm and dragged me down to the ledge, 20' deep. So I didn't have a chance to equalize then. My ear was hurting after the dive and I had to sit out for 2 days in the resort to recover from the barotrauma.
The 1st thumb-up experience
Since that barotrauma incident, I always make sure that if I can't equalize my ears in any dive, I'll thumb-up the dive. One day, 2 of my dive buddies joined me going diving in Flower Garden Banks in Gulf of Mexico. After a rough ride to the site (about 100 miles from Freeport, Texas), I was a bit tired from lack of sleep, but my sinuses seemed OK. I made sure to drink plenty of water & skipped breakfast as the 1st dive was pretty early (7am). We went in for the 1st dive of the day by going down, pulling ourselves down by grabbing the robe, which tied the boat to the site buoy, as there was a slight current. We basically dragged ourselves down one hand grab after another & equalizing my ears between the grabs. I was in front of my 2 dive buddies. Then at one point of a depth perhaps about 12', my left ear refused to equalize. So I turned around & looked to both of my dive buddies, waving them to continue the dive & pointing to my left ear and gave a thumb's up for myself to cancel the dive & went back to the boat. I'm glad I did that for myself without causing my dive buddies to lose a dive that day. After a bit of rest, relaxing & had a cup of coffee & some light breakfast, I tried again on the 2nd dive. It went well. I was able to equalize the left ear. My buddies made all their 6 dives (4 on Saturday & 2 on Sunday) and I had 5 dives (3 on Saturday & 2 on Sunday). Everyone had a great time.