I had my bad panic attack scuba diving in 90 feet of water: that would be on the bottom under 90 feet of water! And, as you said, no for discernible reason at all. We were seasoned divers, Master Scuba Divers and Rescue Divers, with 200 plus dives under our belts. Fortunately, we had enough experience, and were good enough at communicating with each other under water, that I made no attempt to go up but let DH know I was in a bad place and just hung on. (Had I tried to go to the surface, I would have bolted, and going up too fast is extremely dangerous, even fatal.) We were experienced enough that Dive Masters, after the first five minutes or so, never paid us much attention, so I opened my regulator to the max, and added a few rocks to my pockets. We got out of the (awful) current as best we could, and waited it out. It turned out okay: we did the shark dive the next day and dived for the rest of our time in Fiji, but it had a lot to do with our decision to hang up our gear and return to skiing after having concentrated on diving for two decades instead. At least you can't drown skiing!