I have that addition. Will have to look it up"The New Science of Skin and Scuba Diving" - 1968 edition:
View attachment 581211
interpret as you wish...
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I have that addition. Will have to look it up"The New Science of Skin and Scuba Diving" - 1968 edition:
View attachment 581211
interpret as you wish...
?? Selling J-valves? how do you read that into what I posted?The 1963 literature is selling J valves
Sorry my bad. I just saw "Highly recommended... $30". Missed the "despite the price". Doesn't change what I said in my post.?? Selling J-valves? how do you read that into what I posted?
Saying that book is trying to sell you a J-valve is inaccurate and disparaging.Sorry my bad. I just saw "Highly recommended... $30". Missed the "despite the price". Doesn't change what I said in my post.
I know you've given me statistics on PSI needed to surface from various depths and no doubt they are 100% true. I would ask though, would you plan a dive to say, 100' (or even deeper) and plan to begin an ascent with only 300 PSI?
Sorry my bad. I just saw "Highly recommended... $30". Missed the "despite the price". Doesn't change what I said in my post.
I know you've given me statistics on PSI needed to surface from various depths and no doubt they are 100% true. I would ask though, would you plan a dive to say, 100' (or even deeper) and plan to begin an ascent with only 300 PSI?
Saying that book is trying to sell you a J-valve is inaccurate and disparaging.
No, it is not extra air. It is part of your basic air supply that you set aside as a reserve for your ascent. All the J-valve does is alert you that you now need your reserve, and (when pulled down) gives you access to that reserve.I made a mistake, didn't notice the author too, apologized. Rub it in, why don't ya.
My point about ascending with 300 PSI from 100' was worded unclearly on MY part this time. I pointed out myself way back that of course diving is different today--safety stops, maybe being back on board with 500 PSI (as AfterDark just mentioned as well).
I MEANT to ask-- If you were using a J Valve tank 50 years ago would you plan on beginning your ascent from 100' by releasing the J valve pin and using that 300 PSI reserve-- as part of your dive plan back then?
Just trying to get another opinion from a veteran diver, in my quest to determine the all important question-- Is that 300 "extra" air? Is letter "C" correct too?