Is a Computer essential kit?

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Divin'Papaw

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It’s the opposite. I know they can be made without a computer. We were making so called multi level no deco dives 40 years ago using a 120 rule long before computer users claimed it like it was some kind of a revelation. A watch and simple arithmetic which seems to be beyond today’s diver who have been dumbed down by so called technology

This conversation has gotten just hilarious especially when you take into account that it’s occurring on a digital social network hosted in the cloud. Oh the irony.
 

boulderjohn

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It’s the opposite. I know they can be made without a computer. We were making so called multi level no deco dives 40 years ago using a 120 rule long before computer users claimed it like it was some kind of a revelation. A watch and simple arithmetic which seems to be beyond today’s diver who have been dumbed down by so called technology
OK, explain the rule of 120 and how the dives I identified can be done that way.
 

mac64

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OK, explain the rule of 120 and how the dives I identified can be done that way.
I’ve already given a plan for the dives you quoted., but I couldn’t do them without incurring a 10 min deco obligation. But if you or anyone else spent the time at the depth you quoted neither could they. Just because the deco is cleared on the slopes as part of the dive it’s still deco. The same could be done on any shore dive.
 

Jonn

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I’ve already given a plan for the dives you quoted.
When I took my PADI open water 30 years ago I learned and used tables, so I know the basics. They assume a ‘square profile’; if your maximum depth is 120’ and your overall duration is 50 min, you’re pretty bent! That’s a very routine computer dive but the black box is giving me real-time credit for the majority of time spent at much shallower depths.

Is there some more advanced table system that can do what a computer does, without the computer?! Are you noting your depth and time on a slate every minute or two, then tabulating it all manually on the surface or something? That’s obviously possible, it’s not like the computer is magic or anything, but I’ve never seen anyone try. Seems like an enormous task load. How does that 120 rule work?
 

boulderjohn

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I’ve already given a plan for the dives you quoted., but I couldn’t do them without incurring a 10 min deco obligation. But if you or anyone else spent the time at the depth you quoted neither could they. Just because the deco is cleared on the slopes as part of the dive it’s still deco. The same could be done on any shore dive.
You didn't do anything of the sort. You did not provide plans, and all you said you would have to go into deco to do those dives. You never told me how you plan multi-level dives using the tables, and you never told me how "we were making so called multi level no deco dives 40 years ago using a 120 rule long before computer users claimed it like it was some kind of a revelation."

No, you don't have to go into deco on those dives. You don't have to go anywhere near deco on those dives. You do not go into deco and then clear it on the way up. You are never in deco.

So I repeat--how were you doing "multi level no deco dives 40 years ago using a 120 rule"? If you can't explain it here, please stop telling everyone that it is so easily done.
 

mac64

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You didn't do anything of the sort. You did not provide plans, and all you said you would have to go into deco to do those dives. You never told me how you plan multi-level dives using the tables, and you never told me how "we were making so called multi level no deco dives 40 years ago using a 120 rule long before computer users claimed it like it was some kind of a revelation."

No, you don't have to go into deco on those dives. You don't have to go anywhere near deco on those dives. You do not go into deco and then clear it on the way up. You are never in deco.

So I repeat--how were you doing "multi level no deco dives 40 years ago using a 120 rule"? If you can't explain it here, please stop telling everyone that it is so easily done.
95ft/48 minutes EAN 40
1 hour surface interval
80ft/68 minutes
1 hour surface interval
100ft/60 minutes: deco 10min at 10 feet.
There you go again. 20 min NDL at 100 feet: 30 at 90 :40 at 80 : 50 at70: 60 at 60: 100 at 50 every minute over the NDL =1 minute deco at 20 feet no computer needed. If I start at the deepest part of the dive I simply move inshore to shallow water and continue the dive.
 

NothingClever

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vs.

1640981009149.png
 

Jonn

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So you’re doing “multi level diving” by diving one level at a time over multiple dives, with surface intervals between? I suppose that works, you see everything there is to see, do all the diving there is to do, and you don’t “need a computer” to do it. You’re working awfully hard and spending a lot of money to avoid the cheap and easy option though… You might be narrowly correct in your claims but I think I’ll stick with my compy.
 

boulderjohn

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95ft/48 minutes EAN 40
1 hour surface interval
80ft/68 minutes
1 hour surface interval
100ft/60 minutes: deco 10min at 10 feet.
There you go again. 20 min NDL at 100 feet: 30 at 90 :40 at 80 : 50 at70: 60 at 60: 100 at 50 every minute over the NDL =1 minute deco at 20 feet no computer needed.
First of all you gave yourself EANs 40, which cannot be used at 2 of those depths without violating the standard 1.4 PPO2.( I forgot to tell you what I used on those dives, which was EANx 32.)

Next, I am having trouble figuring out what you are doing on each dive. What you wrote makes no sense to me. Are you saying that you can do 20 minutes at 100 feet and then do 30 minutes at 90 feet and then do 40 minutes at 80 feet?

Can you break it down for each of those three dives, as I did?

What algorithm are you using for surface interval times?
 
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