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Hi There

Can anyone offer any feedback on how to calculate the following?

If I’m planning a multi-level dive

My first dive is 29 Mtrs for 20 mins

What is the no decompression limit for my deepest next level permitted.

Any advice would be most appreciated


Cheers
 

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A short fat well off crap cave diver. Likes wrecks
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15,343 Posts
Hi There

Can anyone offer any feedback on how to calculate the following?

If I’m planning a multi-level dive

My first dive is 29 Mtrs for 20 mins

What is the no decompression limit for my deepest next level permitted.

Any advice would be most appreciated


Cheers
More important questions should be

What gas are you on

How much gas have you got?

Whats your SAC?


Just to put you in the picture, using my normal GF deco prifiles I use for OC diving I would be doing 5 mins deco with [email protected] and [email protected] [email protected] folowing 20mins at 29 on air.

If I did a further 12mins at 20m Id be doing 9mins of deco [email protected] [email protected] [email protected]


So if you trying to plan a multi level deco dive on tables id use diferent tables. PADI ones are not all soft and squishy as some people might think.

If your trying to answer a PADI theoretical question then thats a difernet matter.

If not get nitrox 36% and you can do 30 at 29 and 20 at 20 and still have no deco.

ATB

Mark
 

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Jesus don't want me for a sunbeam
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13,407 Posts
On air and OC I allow myself 10min at 30m, 10m at 20m and unlimited time at 10m. For Scottish shore dives it's always a very similar profile and those figures work whatever. I'm sure I should probably be more scientific but I found that most profiles were averaging out not too far from that.
 

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Scuba Tech Philippines
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172 Posts
The use of the term "no decompression limit" strongly hint at a PADI question...probably one relating to the Wheel (tm).

Assuming this is a first dive....calculate the Pressure Group from the first level and then move to the next level (indicated at the inner of the wheel). Starting from that pressure group, follow the depth curve downwards and identify the NDL from the where the curve ends at the NDL mark/outer time ring intersection.
 
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