Hi Alun,
I was the one who effed up the measurements. It had been so long since we'd done a deep dive with the line we've always used. Usually, I'm the one who sets up the line on shore, checks the markings, etc...Instead, I spent the time teaching my sweetie (Jill) the basics of constant weight on a different line. She made a nice new pb of 22.6 metres. But now I've got to show her how to do the same depth with frenzel (which she can do on land already) so she doesn't get squeezed or hurt her ears. Anyway, I went from teaching her to spotting Eric. As I let down the line from the float, I counted 7 line markings for 70 metres. Only 7 markings actually means 80 metres.
Fortunately, this dumb mistake was not distrastrous, although I was surprised to see Mr. Reliable to have trouble recovering on the surface after a 70m dive
. Usually, his LMC dives are few and far between, plus most of the time his tolerance for low O2 is very high, so if he does LMC, I never see it.
I met Eric at 30m and noted that he was looking a little urgent in the last 20m. He stopped kicking briefly at 10m and then kicked the rest of the way up without stopping.
Spotting someone who is diving without a suit is an odd experience because it is so rare to see anyone kicking up from depth with only a speedo on. But it really is an amazing way to dive. I will never compete again with a suit if I can help it.
At 15C, the water is actually too warm on the surface to properly vasoconstrict. You just get cold slowly. It is a lot harder to relax. I usually do a hang below the first significant thermocline to get "puckered up." Then I am able to relax on the surface. This was the first time that Eric tried diving without that first step on a deep dive, I think. If there had been a sharp thermocline along the way, say 12C down to 6C, then it would have been a lot more difficult to relax on the way down. That is what happens in summer here: 20C on the surface and 8C at the bottom, even 6C in some places. Ouch!
Diving with no warm up would really be the only way to do an under the ice dive without a suit. I think you'd have to have some sort of non-compressible neoprene cap on to eliminate brain freeze and ear pain for cold water entering the ear canal. In 1C water you would vasconstrict instantly with great pain, I imagine, and then you'd have less than a minute or so to relax and begin the dive. But I believe it could be done. If Lynn Cox can swim one mile in the Antarctic, then one of us could do deep dive under ice. As long as there is a warm ice hut next to the hole!
Pete
