Is a Computer essential kit?

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arew+4

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When the commie bastards detonate a high altitude nuke and the EMP takes out all the electronics, you'll be singing a different tune then buddy. 😉
 

mac64

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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?
First it was 2 bar then1.8 then1.6. I stayed at 1.6 but like you said it’s only 1.6 for the deepest part of the dive. I’m moving up the reef or shore
 

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. If I start at the deepest part of the dive I simply move inshore to shallow water and continue the dive.
I finally realized most of your post was explaining the rule of 120, which gives the first dive limits for air--100 feet for 20 minutes, etc.
  • It is for air only--you would have to compute equivalent air depths to use for nitrox.
  • It gives the limits for a flat profile dive only--not a multi-level dive.
  • It does not work with repetitive dives.
So nothing in your reply refers to multi-level dives at all. Nothing in your post tells how I would do the dives I did with EANx 32. (I admit I did not tell you that, but the truth is that I could have done those same profiles on air if I had chosen to.)

So you have still not answered ANY of my questions.
 

mac64

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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.
I can dive for 50 euro including fuel.
 

mac64

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I finally realized most of your post was explaining the rule of 120, which gives the first dive limits for air--100 feet for 20 minutes, etc.
  • It is for air only--you would have to compute equivalent air depths to use for nitrox.
  • It gives the limits for a flat profile dive only--not a multi-level dive.
  • It does not work with repetitive dives.
So nothing in your reply refers to multi-level dives at all. Nothing in your post tells how I would do the dives I did with EANx 32. (I admit I did not tell you that, but the truth is that I could have done those same profiles on air if I had chosen to.)

So you have still not answered ANY of my questions.
For nitrox 32 the rule is 130. 100 feet 30min: 90feet 40min: 80 feet 50 min etc . Every minute over the NDL =1 minute deco at 20 feet .
 

Jonn

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If you dive local and have your own gear it’s pretty cheap, ya. Once you travel the cost per minute underwater goes way up of course. People dive into the water (even freezing!) buck naked and have fun doing it; you don’t “need” anything at all. If you’ve got your mechanical timer and depth gauge and stuff and it’s all working the way you want then more power to ya; you can say “I don’t need a computer” and have that make sense. There will always be cases like that but they’re becoming niche cases. Those Sea Hunt reenactors at Silver Springs have a lot of fun without computers too, but there’s not many of them either.

You’re not really making the case that it’s not ‘essential kit’ for most of the diving that most divers do. From a casual tourist on a cruise ship, to a tech diver with a rebreather, you’re not going to get very far without one these days. I think if someone showed up at a resort or liveaboard they’d look silly.
 

mac64

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If you dive local and have your own gear it’s pretty cheap, ya. Once you travel the cost per minute underwater goes way up of course. People dive into the water (even freezing!) buck naked and have fun doing it; you don’t “need” anything at all. If you’ve got your mechanical timer and depth gauge and stuff and it’s all working the way you want then more power to ya; you can say “I don’t need a computer” and have that make sense. There will always be cases like that but they’re becoming niche cases. Those Sea Hunt reenactors at Silver Springs have a lot of fun without computers too, but there’s not many of them either.

You’re not really making the case that it’s not ‘essential kit’ for most of the diving that most divers do. From a casual tourist on a cruise ship, to a tech diver with a rebreather, you’re not going to get very far without one these days. I think if someone showed up at a resort or liveaboard they’d look silly.
The OP is shore diving locally to a max of 18 metres why does he need a computer?
 

KenGordon

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You said:





Well, I named dives that you apparently think cannot be made without a computer. Those divers were not near NDLs. Dives that are not at the same depth the entire time are called multi-level dives. If you look up the phrase, you can learn all about them,
For decades there have been tables that will let you do these dives. Stops might be involved but they are doable.

The OP doesn’t require computer. It may not allow longer dives or reduce stops if the deco is not the limiting factor on the dive. They are helpful in other ways, such as logging.
 
https://www.shearwater.com/products/peregrine/

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