I was an experienced diver with 50+ dives in a diverse range of situations. My wife got her certification so I took her diving in one of the lakes surrounding Phoenix AZ. We had been down about 15 minutes and were at 40 feet of fresh water. I kept my eye on her except when I had to turn my head to see her as she changed sides often. I turned my head to see my wife with no regulator in her mouth. I freaked! I gave her my buddy regulator. She put it in her mouth then spit it out! I freaked again! I ripped my regulator out of my mouth and gave it to her. She took it and spit it out! At this point I quickly calculated that we could go to the surface and have no issues with the bends, so I grabbed her and pushed her up as hard as I could. I spent the whole time going up without a regulator as she did the same. Total freak out on my part. But I got her to the surface and only lost a fin in the process. We have been together for 22 years and will hopefully get 20 more.
I talked with her after I had recovered my senses and she had settled down. She had spit her (Very expensive, easy to breath) regulator out of her mouth because it had water in it. She spit out my extra regulator because it had water in it. She spit out my (far less expensive) regulator because it also had water in it. She had forgotten the purge valve. Needless to say, she survived as did I. She has had enough of diving and doesn't enter the water. In my 200+ dives, this is the only time I have freaked out and hopefully the only time I freak until I die.