Where did the 135 foot / 40 meter recreational max depth limit come from?

[lexvil]

the proper answer would be from the NAVY dive tables which were adopted for recreational diving.

but alas, the no-deco time (NAVY Tables) at 130' was considered the minimum allowable to actually get any work done...

If memory serves the NDL on the old tables showed 5min to well over/under 200ft for a single dive.
As a note I have looked for the tables I used when I started and can’t find them so I just went on a net search and found a set of 1958 USN tables so I bought it.

 

[Wookie]

You are just not patient enough. Give them another five minutes and they will be arguing over the middle name of the dog that ate out of the dumpster at the LA YMCA and the influence it had on the process of Laminating dive tables which resulted in the adoption of the color scheme that was adopted by the printer of the first edition of the Science of Scuba diving and resulted in a font choice that limited the number of columns that ended up in only being able to go to 130’ on a page. Hence the 130’ limit.

Wait until the Recreational Dive Planner™ enters the conversation. Remember, 95% of divers know nothing else.

 

[scubadada]

I have heard many explanations. The earliest training organizations, LA County, etc., adopted the USN tables, all that was available. The Navy had determined that the no deco limit at 130 ft of 10 min was the shortest time that productive work could be done. The no deco limit at 140 ft was also 10 min, giving a little depth leeway. The Navy may have required permission to dive below the 130 foot limit.

There may be other reasons that this depth was chosen for rec diving. Rec equipment in the 1950s may not have performed well below this limit. Air consumption at this depth was rapid. Nitrogen narcosis commonly occurred.

I look forward to hearing the real story

 

[Wookie]

The Navy may have required permission to dive below the 130 foot limit.

The navy still requires permission to dive, period. If you're diving below 130 the amount of required equipment and planning and permissions get unwieldy.

Which is one reason I dive for the navy.

 

[captain]

I have heard many explanations. The earliest training organizations, LA County, etc., adopted the USN tables, all that was available. The Navy had determined that the no deco limit at 130 ft of 10 min was the shortest time that productive work could be done. The no deco limit at 140 ft was also 10 min, giving a little depth leeway. The Navy may have required permission to dive below the 130 foot limit.

There may be other reasons that this depth was chosen for rec diving. Rec equipment in the 1950s may not have performed well below this limit. Air consumption at this depth was rapid. Nitrogen narcosis commonly occurred.

I look forward to hearing the real story

I think you came as close as anyone can get. It was probably based on this page in the 1958 Navy diving manual.

 

[MiloR]

You are just not patient enough. Give them another five minutes and they will be arguing over the middle name of the dog that ate out of the dumpster at the LA YMCA and the influence it had on the process of Laminating dive tables which resulted in the adoption of the color scheme that was adopted by the printer of the first edition of the Science of Scuba diving and resulted in a font choice that limited the number of columns that ended up in only being able to go to 130’ on a page. Hence the 130’ limit.

This would be the summary of scubaboard.com if it were a book, movie, or tv show.

Occasionally I have to look at the address bar to see if I accidentally logged into scubaBORED.com, Boredom and/or ego are the only things that can explain how some conversations derail like they do, lol.

 

[captain]

All the people involved with setting up the training are no longer with us so we may never know.
Here is where to start looking but the new web site is not working.

L.A. County Scuba Launches New Website - California Diving News

http://www.lacountyscuba.com/

 

[Storker]

No matter the history, given what we know now limiting simple rec diving to max depths around 30-40m (100-130') seems like a pretty good idea. Onset of noticeable nark, breathing gas density, risk of owing serious deco you don't have enough gas to handle, there are enough reasons to limit your non-tech dive to 30-40m.

 

[scubadada]

Where did the 135 foot / 40 meter recreational max depth limit come from?

@Sam Miller III

Where did the rec limit come from?

Thanks, Craig

 

[Angelo Farina]

When was the recreational limit reduced to 40m?
When I was certified in the seventies, the limit was 50m, and deco was allowed, but only if starting at 9m (that is, three deco stops maximum, 9m, 6m, 3m).
My 3-stars FIPS-CMAS certificate, issued in 1977, fixed my limits for recreational diving at 50m with deco, with buddy, in air, and 10m, within "oxygen safety curve", with buddy, with pure-oxygen rebreather.
I really do not know in which year the maximum depth was reduced from 50m to 40m, and the NDL was enforced as the limit for recreational diving.
So I am asking if someone knows the dates where the various agencies reduced the rec limits...