Omega Seamaster 600 166.077

A CollectΩr's Guide

Begin the journey


The Seamaster 600 is undoubtedly the most recognisable watch ever made by Omega. Its complex design history has given rise to an often quoted but inaccurate timeline perpetuated by reference books which have unfortunately been relied upon to the detriment of collectors.

The objective of this short guide is to assist the collector in correctly understanding the main points in identifying this watch in all its variations. The Guide does NOT go into all the detail amassed by the author in researching this model.

‘The Omega Ploprof’ is an inappropriate title for the Seamaster 600 arising out of an error repeated in an earlier reference book. Ploprof applies to both the Seamaster 600 and the Seamaster 1000 watches but less than rigorous research failed to notice the distinctions as a consequence the true timelines were lost.

The History

In the late 1960s underwater exploration, off-shore oil constructions and maintenance, as well as applications such as scuba diving, water sports, and sub-aqua military and naval special forces, saw an increase in demand for underwater watches.

The number of employees of underwater contractors at the time exceeded 3000 of which a 1500 were commercial divers.

So the demand for a robust, waterproof, legible, reliable and high-depth rated watch caused the development by Omega of the unmistakable Seamaster 600 debuting at the 1969 Basel Show and being issued for retail sale in April 1971.

Pre-production prototype identical to the 1st issue but with a dial zero.

Despite it being a superb professional divers watch it also had a big following in the retail market.

Gianni Agnelli, the chairman of Ferrari and Fiat and one of the most prominent public figures in Italy had an allergy to the metals used in watch cases.

This led him to wear his Seamaster 600 on the outside of his cuff and this idiosyncratic display enhanced the watches visibility and hugely boosted demand.

Gianni Agnelli wearing the Proplof



The Correct Chronology of the Watch

In order to correct the previously invalid chronology of the watches, it was necessary to seek independent verification of what the watches looked like at the production stage.

With this particular model given the rate of attrition, and the more than average frequency of swapping of movements, dials, bezels and even cases it became vitally important to reference independent, reliable documentation. A cursory examination of Seamaster 600s that were photographed and went for service at Omega Bienne shows that over 60% have suffered a movement swap.

So for the purposes of confirmation, the Author has included internal documentation held in the Omega archives detailing the watches original built specification and subsequent configurations.

Omega archives

Original registered design patent for the MARK 1 watch, 1st edition retail.

Omega archives

Omega archives: Press release issued in February 1971 announcing the arrival of the MARK 1 1st edition watch shown on the isofrane strap with the red plastic lock nut.


First catalogue

One of the first printed catalogues specific for the US market dated February 1971 showing the watch to be available for order and delivery from April 1971. Note this is the MARK 1 watch, 2nd edition with the steel replacement lock nut.

Omega archive documentation

Production specification for the MARK 1, 1st edition watch isofrane strap, red plastic lock nut, but indicating the option for a 1162/162 steel bracelet


Omega archive’s internal documentation

MARK 1 watch 2nd edition, showing the transition to a steel lock nut

Omega archive’s internal documentation

MARK 3 watch showing the D3 dial, B2 bezel now on the mesh bracelet onwards from 1975


MARK 3 watch showing the range of optional metal bracelets

Because of a lack of rigorous research in this model, the important connections between the Seamaster 600 (Ploprof 0) and the Seamaster 1000 (Ploprof 1) have been ignored.  In 1972 both watches were available with identical dials, identical hands, identical bezel designs and identical calibre movements. The Seamaster 1000 of this period is extremely rare and for more information collectors should refer to




Prototype with red plastic crown lock nut, never issued for retail.

A prototype for the MARK 1, 2nd edition with a painted red steel nut as opposed to plastic, this was never adopted.


Prototype with early 1001 calibre movement, pre-production, unnumbered, 1968/69

Above is an example of a very early prototype movement as used in the Seamaster Ploprof 600

A COMEX prototype sold in 2016 for over £75,000.

Prototypes in various configurations usually sell upwards of £40,000. Unfortunately due to mishandling and part swaps during service completely original configurations are hard to find


Bezel B1 – Used on prototypes and seen on MARK 1 edition watches from 1971

Bezel B1

‘1’  with serif, round top 3, thicker print, triangle shaped 10 minute point markers.

Bezel B1 Service A

Same as B1 with lighter print, close loop 5

Bezel B1 Service B

Same as B1 but with luminova, open loop 5, flat top 4

Bezel B2 seen on MARK 2 edition watches from January 1972

Bezel B2

No serif 1, flat top 3, pentagon shaped 10 minute point markers. This can also be seen with slightly heavier print.

Bezel B2 A

Reprint bezel, but printed very heavily with the 20 30 and 40 touching the minute markers.

Bezel B2 B

Heavily overprinted, seen on later edition watches.


Bezel differences under UV light


First issue Comex stud or pusher case  case, in-pressed inverted stamp marking, right hand crown.

Retail production case interior

Different case stampings

Case Graining

Note the graining on the case, the lock nut and the crown. Typical of the very first production watches.


Case 1

Original prototype, ‘U’ shaped cutout for crown and later plastic lock nut inverted stud case not seen on retail version

Case 2

MARK 1 ‘U’ shaped cutout for crown and with metal lock nut retail configuration from 1971 on

Case 3

MARK 2 ‘C’ shaped cutout

The ‘C’ shaped cutout case is only seen on 1972 watches always with the drop 600 dial Thought to be an improvement on the plastic lock nut to prevent silt build up

The cutout is probably later milled hence the variation in depth and rebate seen

The original lock nuts were steel, however professional divers never bothered to clean their watches in fresh water after work and mud, silt and salt residue was thought to build up on the threads of the lock nut and thereby impede its ability to be unscrewed. So the engineers devised a plastic nut to take it’s place. This was too easy to cross-thread and so after a short period in the retail market they reverted back to steel.

COMEX Note & Invalid Assumptions

First, it must be stated that there is no evidence that Jacques Cousteau was involved in the design of this watch. Secondly, the watch did not hit the retail market until April 1971, not 1970.

The watch was designed to meet the requirements of the sub aqua market and was put forward in prototype form along with the Seamaster 1000 to the biggest underwater contractor at that time COMEX for their input and live testing

In the course of those trials, COMEX requested a darker blue dial to increase the contrast ratios and hence dial D3 was born with much higher colour saturation.

This additional pigment electrolytic reaction with the brass blank  is believed to have contributed to the much higher rate of corrosion seen on these dials and thus dial D3 was regularly swapped out at service with the more impermeable dial D2 hence accounting for the appearance of the D2 dial on much later watches thus creating the invalid assumptions made about the timeline of the dial.

Because of a titling mistake in the so called reference book for this watch, it was held out as being called the “Ploprof”, when in fact it was the 2nd of two ploprofs, the 1st being the 1000, a mistake which blurred the true history of this watch.


COMEX History

In the very early years of underwater exploration, inner space as it came to be known, one of the most innovative companies called COMEX was the main player. From 1968 until the end of 1970, Omega supplied COMEX exclusively to develop the most highly engineered professional dive watches in existence at that time.

A book on the Ploprof models, the relationship to COMEX and its place in history of professional diving is in the making but halted due to covid however


When published in due course, in  the Ploprofs will be more properly understood in the context of divers watches and their history.

Omega watches were extensively used and tested during COMEX diving and exploration missions taking place between 1968 – 1970.


Physalie I – 05 March 1968

In 1964, Comex put together a team of specialists and invented the first hyperbaric chamber which was capable to simulate the pressure of underwater diving in a controlled area in the company’s own research laboratory.  COMEX founder Henri Germain Delauze and Dr. Ralph Werner Brauer descended to the equivalent pressure of 1100 ft/335 m below sea level in a pressure chamber at the Comex Hyperbaric Center in Marseille.

Physalie II & III – 11 June 1968 & 27 June 1968

Following up the major achievements of the Physalie I experiment, Comex conducted the Physaline II & III close after another. Both experimental dives were conducted by Dr. Ralph Werner Brauer and Comex diver and engineer René Veyrunes

During Physalie II, a total of 2 hours of compression time was required to reach the maximum depth of 1180 ft/360 m. Brauer and Veyrunes spent 77 minutes below the level of 990 ft/300m which resulted in a total duration of decompression of 116 hours, equaling 5 days before pressurising to sea level again and being able to leave the hyperbaric chamber again. 

Janus I – 17 October 1968

Operation Janus I marks a cornerstone of commercial diving history since Comex sent 4 divers specialised and trained for underwater engineering tasks to live in a deep sea habitat, performing underwater repair and maintenance tasks on a wellhead in a depth of 500 ft/152 m.

The divers spent a total of five days in their offshore habitat in a storage depth of 290 ft/ 88 m and had to carry out multiple tasks at a working level of  500 ft/152 m und constant and full saturation of their bodies. 

Hydra I – 28 October 1968

After successfully conducting a row of Physalie experiments, Dr. Ralph Werner Brauer wanted to apply his experience from hyperbolic chamber dives to deep sea diving in the open water. Operation Hydra was a joint venture of Comex and the Wrightsville laboratory with the primary objective to explore the use of hydrogen in the divers breathing gas to overcome oxygen toxicity and nitrogen narcosis in a depth of 1000 ft/300 m. 

Janus II – 16 September 1970

Following up the great success of Operation Janus I in late 1968, Comex decided to follow up with an additional dive of the Janus program, descending Patrick Cadiou, Christian Cornillaux and Michel Liogier even deeper down the open water to a maximum depth of 840 ft/256 m.

The team spent a total of nine days in their offshore habitat in a storage depth of 656 ft/ 200 m and had to carry out multiple tasks at a working level of 840 ft/256 m und constant and full saturation of their bodies.

Physalie IV & V – 24 September 1968 & 19 November 1970

During the past years, Comex was constantly pushing the boundaries of deep sea exploration and research to emerge as the leading force in commercial saturation diving. 

Physalie IV took place in late 1968, taking the divers to a maximum depth pressure equivalent of 990 ft/ 300 m and could not catch up with the depths achieved in the earlier Physalie operations. The team spent 10 minutes at the maximum pressure level before starting a total of 106 hours of decompression.

Physalie V, conducted in late 1970 on the other hand was a great success, establishing yet another depth record as the two divers reached a pressure equivalent of 1706 ft/520 m below sea level.


This is undoubtedly the most distinctive feature of the watch and the most misunderstood.

These dials were made by Beyeler and were part number 1427. In addition to the blue dials there is a batch of the D3 dials which appear black and although there is no official explanation of this, it appears to be a consequence of degradation An example of the black dial is included below.

Singal line Dial Zeros [monoscript] are the ONLY Comex dials and it is understood that these dials were recalled for overprint to create Dial D1 when it was discovered there were insufficient dials for the retail launch

The Beyeler quoted  production time was six months, but Omega wanted to be available for the Basel  launch in 1971

Two things mandated the urgency of launch.

Firstly, Omega refused to allow Comex to be a distributor and  secondly, the need for watches  to be worn by divers to determine elapsed time for decompression, and oxygen usage became redundant due to saturation diving.




Dial D Zero

Mid blue coloured dial, never used for retail

Dial D1

dial Zero with over print

Dial D2

Dial D3

Darker blue (see COMEX note above)

Dial D3 Black

Black dial

Dial D4

Flat-top ‘A’ in ‘automatic’

Dial D5

The last iteration with oval zeros. Sharp ‘A’ in ‘automatic’

Dial D6

Service dial with tritium markers. Note the lume touches the date window.

Dial D7

Service dial luminova not tritium, note the lume touches the date window

Dial Lettering


Dial D Zero – Single text print, used for pre-production and prototypes

Dial D1 – Overprinted text ‘Professional’ and ‘600’ sandwiching ‘Seamaster’. Note the squashed lettering and the sharp ‘A’ in the word ‘Professional’ and the dumpy ‘600’

Dial D2 – Single print dial with spaced-out ‘Professional’, flat-top ‘A’ and  same print density

Dial D3 – Sandwiched 600, darker print showing dial degradation due to paint/dial corrosion

Dial D4 & D5, oval zeros, feet and metres, sandwich 600

Dial D6 – heavier font, rounder zeros, feet and meters, sandwich 600


Dial Corrosion & Blistering

D2 dial front and back composition. Front showing blistering as a result of using the new heavier pigment. Back top-edge of the Beyeler-made (part no. 1427) dial showing the beginning of chemical corrosion.


The hands were of the plongeur style and the hour hand had four variations.


Straps / Bracelets

The first watches were seen on isofrane straps in the following colours –

An optional extra was a steel bracelet 1162 with 162 end links.

From 1975 onwards along with the Seamaster 1000 it was offered on the shark mesh bracelet in 24mm.


Prototypes are often seen with the 1000 calibre movement but in later iterations and with the retail watches the 1002 movement was standard.

This was an enormously robust movement. Probably one of the very last movements exclusively designed by Omega and it was a high beat 28800vph with instantaneous date change at midnight and first issued in 1968.

This was a very common movement with over 370,000 made but it experienced occasional longevity problems. So when a watch was presented for service a movement was swapped out in its entirety.

This has given rise to over 60% of sampled watches having undergone a movement swap.



Click to enlarge and view full image


This appears to be an example of the black dial version.

Thank you to Old Omegas for their catalogue contributions.


Click to enlarge

The photograph above was very kindly provided by Jonni K.  and is incredibly interesting as it shows an extremely rare photograph of the proposed titanium version of the 600. This appeared in adverts in separate dive magazines in Finland.

The catalogues after 1971 where merely representational and not accurate pictures of available watches.


Years of Production

The MARK 1 1st edition was offered in January 1971 but it appears that production didn’t start until the middle of that year. The watch lasted for approximately 8 or 9 years. More detail will be provided in an upcoming book. Movement number ranges are in batches are not contiguous.

Price & Value

Historic values have been skewed by bad research where people have paid higher prices for watches they believe to be early versions.

A watch in good condition with the correct papers or confirmed by archives is worth a premium of at least 20% higher than a regular watch Prototypes are worth £50,000 to £150,000 as confirmed by recent prices.

The prices below are relevant to watches in excellent condition, all original, collector quality and fully original with extract.

Update (2023 ): Yet again new prices are confirming that any watch which is pre-production and has an interesting provenance will go for 5-7 times standard values.

Overprint drop 600.     FIRST  retail

average condition £5-7000     Good condition  £8-15000+

A big range determined by condition and interesting features

Sandwich 600 C CASE 1972

Average condition £6-7000     Good condition £8-£12000+

Sandwich 600 Non-C case 1972/3

Average condition £5-6000   Good condition £7-10,000

Drop 600 1973 …

Average  condition  £6-7000   Good condition £8-10,000+

Feet and metres 1975…1980
Probably the most common iteration

This watch comes with two bezel  versions

Average condition £6-8000   Good condition £9-11,000+

Single line or mono script pre-1971, with correct stud case ex COMEX 

For this watch to reach the below values, everything has to be correct.


For this Watch to reach the below values, everything has to be correct. Please note, the dial alone is worth a minimum of €25-€30,000

Average condition £110-£120,000  Good condition £130-£150,000

These watches are extremely difficult to value because it all depends on condition and provenance.
There is currently a very well provenanced and important single line Ploprof 600 known  to be used by a named COMEX  diver

where the owner has turned down over. £300,000 !! 

This site will start to correct prices once the market reevaluates the new information now available. It should be noted that this watch is rarer than most people realise in any original iteration.

In Review

Firstly this whole work is free to read, and please use it and quote from it without inhibition, but  I would ask would be to give attribution  when copied so that others may be lead to the source

It’s worth mentioning that this is an ongoing work. The more info provided by the collector community at large the more i can refine and perfect this and future websites


Do not use this site as a template to try to create so-called prototypes and Frankenstein‘s

At the outset I made it perfectly clear that I have not included all my research in this document, I have deliberately left out important detail, so I will be able to catch you out quite quickly, something which I have been doing for the last 30 years very successfully


This side is the benefit collectors, and so feel free to contact me with any queries whatsoever, and for any proposed purchases, please note, it is always better to ask me before you buy rather than afterwards for obvious reasons

As previously stated I have done a lot of work in researching and supporting the important heritage of the Seamaster dive watches and in particular in reference to COMEX.

Amazingly I am finding out more about the iterations of watch on a regular basis

I will be collaborating with important collectors in the production of this future publication so feel free to contact me  or with any information that you feel would be helpful.

About The Author

This website was created by a former Professor and collector for over 50 years.

In order not to hamper his research he prefers to remain anonymous however he can be found on Instagram @t_solo_t.

He’s happy to be emailed for all or any questions at

Sincere Thanks

Particular thanks to the Omega Museum. To Merlin the important COMEX Omega collector for the photos of his wonderful watch. To Maurizio Cozzani @plock33, an enthusiastic and knowledgeable collector who has kindly provided rare prototype images and finally to @vintagewatchzilla, a very able collaborator, collector and generally acknowledged schnitzel King of Vienna.

This site is dedicated to ANDREA and MARTINA. Rosie, Jake, Bella and Bear