I went climbing recently with a friend to do some dws. Was a good evening, calm seas, warm etc. Did some routes then tried a steep roof. Was upside down for a good 45 seconds or so trying pretty hard on a couple of moves then cut loose and swung round and fell a bit awkwardly front first into the water, although nothing too dramatic. I came up and made a joke to my friend about him filming it so he obviously thought all was ok. He then started to pack a couple of bits away and carried on filming for a few seconds without realising.

I then took a couple of strokes and blacked out. At some point shortly after after (probably only a few seconds) I inhaled sea water and came to completely disoriented having no idea where I was or why I was in water. Was scary. I managed to swim to the side and pulled myself together and we climbed out.

I think I blacked out because I'd been pulling pretty hard for a while basically upside down, then spun around and hit the sea, which although warm, is British warm. Probably wasn't breathing enough whilst trying the moves. Essentially not enough oxygen and some relevant stuff here https://www.rlss.org.uk/shallow-water-blackout-hyperventilation-and-breath-... 39

Have got it on film including moment I pass out if anyone thinks that'll help, but probably unnecessary.

I've never blacked out before (to best of my knowledge).