Big Heavy tanks!

[berndo]

e.g. berndo suggests determining that the buddy has 40-50 min of time with a 12l tank at roughly the same depth, from conversation.

It's a more reliable method than 'finding out' the sac rate sitting on a couch as it's information from actual, real world experience. What you're doing with the 1.5 or whatever factor is pure guesswork.

 

[steinbil]

This is also fake news. You must have not read the training material of your OWD class. How to calculate sac is in the OWD training material. People just don't do it after the class because there is no point in doing it.

Gas planning is an important skill for autonomous divers. If you only dive with supervision (follow the DM), you can get away with not knowing. However the OWD certifies you as an autonomous diver, hence gas planning should be taught and practiced.

 

[berndo]

Gas planning is an important skill for autonomous divers. If you only dive with supervision (follow the DM), you can get away with not knowing. However the OWD certifies you as an autonomous diver, hence gas planning should be taught and practiced.

It's simply not true.
Doing half plus x tank IS gas planing. How people (how claim they dive) don't undertand this simple and perfectly fine concept, is beyond me. It has nothing to do with following a DM or any kind of supervision.
I suggest more diving, less comming up with theories behind the computer.

 

[Wibble]

@berndo: why do you disagree with my REASONABLE AND STANDARD CALCULATIONS?

Do you understand it, or are you just making some other point?

 

[Wibble]

No, the dive does NOT end at 100 bar (more fake news). It's the TURING pressure at which you swim back. Nobody ever said in this thread or elsewhere that a dive ends with 100 bar.

It is a NDL dive. Not a cave dive, or some other swim to an end point.

It IS the point you MUST surface.

 

[berndo]

It is a NDL dive. Not a cave dive, or some other swim to an end point.

It IS the point you MUST surface.

100 bar is NOT the end of the dive, it's the TURNING point. Stop with this nonsense claims. I'm not going over this again.

 

[berndo]

I suppose this is one of the reasons for which not-US based agencies, such as CMAS and BSAC, teach these calculations at the very basic level, whilst US-based agencies shift this training to more advanced levels.

Unless is was taken out recently, sac calculation is in the PADI and SSI OWD class and in the training material. What people have said here is not true.

 

[steinbil]

It's simply not true.
Doing half plus x tank IS gas planing. How people (how claim they dive) don't undertand this simple and perfectly fine concept, is beyond me. It has nothing to do with following a DM or any kind of supervision.
I suggest more diving, less comming up with theories behind the computer.

An OW diver does a boat dive on a 18m shipwreck with their buddy. How are they going to answer these questions:

- At what gas pressure should they start the ascent to be on the boat with 500PSI?
- How much gas do they need in a gas sharing ascent from the bottom?

PS.
The condescending tone is getting old and, frankly, quite boring.

 

[Wibble]

100 bar is NOT the end of the dive, it's the TURNING point. Stop with this nonsense claims. I'm not going over this agian.

You are WRONG and are being misleading and giving potentially dangerous advice.

The correct answer is 100 bar MIGHT BE the end of the dive, you need to calculate the amount of gas YOU require to get back into the boat/beach with sufficient reserves that you don't run out of gas.

Your dogma is showing. It is important for newer divers to understand how to work out their actual requirements. I refer to my previous calculation for you to read and understand as you clearly have not worked through it nor understand it.

Big Heavy tanks!

I'm not asserting that either one is more "correct" as there appears not to be a consensus, but I observe that Wibble's definition is not the same as SDI's definition -- I was using the one from SDI. It seems that experienced divers disagree on the exact method of gas planning -- e.g. berndo...

scubaboard.com

 

[Angelo Farina]

Unless is was taken out recently, sac calculation is in the PADI and SSI OWD class and in the training material. What people have said here is not true.

My sons were first certified OW and AOW with PADI. 2 days each course.
Later, after seeing how little they were taught, I sent them to a true, 3-months long CMAS course.
Albeit in the PADI training the concept of SAC was explained, they were never asked to do actual calculations on how much bars are required for a given dive, taking into account tank size, initial pressure, personal SAC and dive profile. This instead was explicitly required in the following CMAS course.