Paladin
Contributor
Does anybody still use the "120 Rule?" Years ago, it was a handy tool to use when tables weren't available.
120 Rule
- Thread starter Paladin
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The general idea of the 120 rule is a rough way to calculate the No Decopmressison limits for air:
120 - average depth = NDL
For example:
dive to 60 feet >> 120 - 60 = 60 min NDL
dive to 80 feet >> 120 - 80 = 40 NDL
This is NOT an exact science, just a "general idea'
***DISCLAIMER *** never base a dive plan on ANYTHING you read from some guy on ther Internet... just sayin'
120 - average depth = NDL
For example:
dive to 60 feet >> 120 - 60 = 60 min NDL
dive to 80 feet >> 120 - 80 = 40 NDL
This is NOT an exact science, just a "general idea'
***DISCLAIMER *** never base a dive plan on ANYTHING you read from some guy on ther Internet... just sayin'
Sorry, I though you asked, "what is the 120 rule" ...doh!
To answer your question... sometimes... but not often.
To answer your question... sometimes... but not often.
ianr33
Contributor
I used it one day when I forgot to pack my computer.
JohnB47
Contributor
There is a Web site Precision Diving that mentions it as a dive planning tool.
Scott L
Contributor
Never mind.
Sinbad the Diver
Contributor
Blackwood
Contributor
Yes, for single (i.e. non-repet) dives I'll use the 120 rule (adjusted for the gas I'm breathing).
nolatom
Contributor
used it once when I forgot to turn the computer on before first dive. Then tables for second dive. Seems like a useful backup thing to remember if you goofed up as I did.
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