NoDeCo bezels from the 1960's - Dive tables question

[Flying Doctor]

I'm hoping someone may be able to point me in the right direction, please. I'm looking into the NoDeCo bezels from the 1960s. DOXA is probably the most well known but Eterna had a Super-Kontiki with one before DOXA.

Quick bit of background. The Eterna was released in 1961 and the patent says they used the French Navy tables. DOXA was 1967 for the SUB 300. The SUB 300T released a year later definitely used the US Navy tables for the Imperial bezel but the metric one stayed the same as the earlier SUB 300. I've attached a pic of the Metric SUB 300.

I have the 1961 French tables which I've attached an image, but unless I'm making some fundamental mistake, the tables show at 20 meters you have 60 minutes maximum without having to do a decompression and at 30 meters you have 30 mins maximum. The DOXA bezel shows 50 minutes at 20 meters and 25 minutes at 30 meters. The Eterna numbers match the DOXA ones so I guessed they used the same tables, but not the 1961.

I can't find any earlier French navy tables. But I wonder even if there were ones from say 10 years earlier, would the NoDeCo limits change that much? I think the Swiss Bühlmann tables came much later than 1964 so it probably wasn't them.

I'm at dead end trying to figure out which tables DOXA would have used.

I know this may be a bit of a mission impossible but thought I'd stop by and ask.

Thanks for having a look

 

[tursiops]

The doxawatches website makes it clear that the US Navy tables were used, and the YouTube video they link to shows the imperial version which clearly matches the USN tables of the time; your metric version is just a conversion of the same table. Noting fancy, just the US Navy table of the time. The clue is that this is the table that the Rule of 120 was derived from, i.e. Depth(ft) plus Time(mins)=120 for depths of 60-90 ft. Above and below those depths D+T added to a somewhat larger number...so if you stuck with 120 you'd be safe for all depths. Many of the scuba watch dive bands of the time had those numbers printed on them. This all worked fine for the first (and only) dive of the day; you could not safely use those numbers for a repetitive dive. FYI, the Imperial-Metric conversion of that table was rounded to: 40 ft = 12m; 50 ft =15m; 60 ft = 18m; 70 ft=21m; etc. Every 3m was = 10 ft. Up to 140 ft = 42m. The later versions of that table stopped there with no-deco-times.

 

[Flying Doctor]

Thanks for the reply. Full disclosure, I'm the guy who wrote the DOXA books. Most of their historical knowledge comes from my books. DOXA went bust in 1997 after being owned by Synchron and Aubry from 1970. There was next to no information transfer. The whole thing about the bezel being based on the US Navy tables was from a conversation with a DOXA employee from the 1960s done in 2002. Some of what he said is incorrect. I'm writing a new book on the Vintage SUBs to correct a bunch of history that is in error, a great deal of it from my books! But they were based on the limited information available at the time and unfortunately a lot of marketing people now are not burdened by letting facts get in the way of a good story

Definitely, the 300T Imperial bezel is based on the US Navy tables. Item for item. But I'm not convinced the Metric one is. Here's a spreadsheet showing the US Navy, the Metric DOXA and a Meters to Feet. It doesn't quite parse to me. Meters to Feet - 131 feet shows 15 mins time, US Navy 130 feet shows 10 minutes. 147 Meters to Feet shows 10 minutes, US Navy 150 feet shows 5 minutes.

I used 1 meter = 3 feet 3 inches but even using 3 meters = 10 feet it doesn't quite align. For example 45 meters on the DOXA bezel gives 10 minutes. 45m x 3.3333333 = 149.99999. Lets call it 150. US Navy at 150 shows 5 minutes.

The Metric DOXA numbers match the Eterna bezel numbers and they state it is the French tables that they used.

To be honest with you, you may be absolutely right and the US Navy tables were used for the original SUB 300 Metric bezel. I made so many mistakes in the past relying on old bulletin board messages and my mate who knew someone who worked for someone said that.......... you know how that goes, so I'm trying to correct the stuff I was in error with and try to find trhe facts behind stuff now. I won't even start on the HEV story. That chapter is 25 pages

Thanks again

 

[JMBL]

First French Navy dive table were the GERS 65 (Groupe d'Etudes et de Recherches Sous-marine : Ph.Tailliez was the boss, and J-Y Cousteau n°2 ; 65 stands for 1965). This table was replaced by the MN 90 (Marine Nationale 1990) which was made compulsory for training around 1991.

Prior to 1965, French Navy dabbled with Haldane's original dive table.

 

[Flying Doctor]

Thanks. GERS 65 would be too late for the Eterna bezel, but I did see in a posting on a French site someone mention GERS 59 as well as GERS 65. I could never find anything on GERS 59. So must have been an error if the 65 were first.

 

[JMBL]

Now that you speak of it... I'll have a look in my books today and might find something.

 

[tursiops]

Thanks. GERS 65 would be too late for the Eterna bezel, but I did see in a posting on a French site someone mention GERS 59 as well as GERS 65. I could never find anything on GERS 59. So must have been an error if the 65 were first.

I think Gers 58 were the original USNavy tables, but I'm sitting in an airport and can't check. Look on Wikipedia for History of Dive Tables.

 

[JMBL]

I think Gers 58 were the original USNavy tables, but I'm sitting in an airport and can't check. Look on Wikipedia for History of Dive Tables.

That's very likely.

 

[Flying Doctor]

Just saw this in an old French forum post (2009) where they talk about differences from GERS 59 to GERS 65.

"Before the GERS 59, we were more reasonable by already setting the limit.

without a level at 20m/50mn, 26m/32mn, 30m/25mn, 40m/15min (in the 1955 edition).

The same goes for the GRS table (Edition 1949, page 68) which gave the same

values, except for the 40m which were reduced to 13 minutes''

The 1955 edition numbers are a better match for the DOXA Bezel.

So I have to ask myself why would DOXA and Eterna and ZRC (the other company with NoDeCo bezel in 1963) use US Navy tables. They were Swiss, German and French companies. I have proof Albert Falco helped DOXA with the SUB 300. It was designed initially for the European market. I'm sure Cousteau and his guys would be using French tables. I know that Aquastar used the 1961 French tables when they designed the Deepstar bezel. I know Marc Jasinski who was the designer and patent holder. The tables in my first post are from him.

The SUB 300T Imperial uses the US Navy because that watch was sold by in the US by US Divers which is why it has the US Divers logo on it.

In the end I'll probably never know for certain but at least I'm trying to find out and want to say thanks to you guys for chipping in.

 

[Flying Doctor]

Little bit more on the 1955 edition

The 1955 edition, published by Arthaud, of the original 1949 book by Tailliez, Cousteau, Alinat, Devilla, and Dumas, representing GROUPE D ETUDES ET DE RECHERCHES SOUS-MARIN (GERS). The first book published on diving with the Aqualung by the first military unit to be formed around the Aqualung. The text is French. The book is authored by Cousteau and the GERS team and presented by the French MARINE NATIONALE.