Omega Seamaster 600 Plongeur Professionnel “PloProf” MK1 – 166.077


The Seamaster 600 Plongeur Professionnel, or “PloProf,” Ref: 166.077 Mk11, is undoubtedly the most recognisable watch ever produced by Omega.

Nothing, but nothing looks like a PloProf!

The need for a highly legible, sturdy, high-depth rated watch to keep divers safe grew in the late 1960s as a whole new world of underwater exploration, oil rig building, sub-aqua military special forces, and not to mention civilian pleasure scuba diving emerged. The “PloProf,” was introduced by Omega at the 1969 Basel Watch Show and available for purchase starting in April 1971. Ever since, it has ruled the seas!

Professional divers rarely took the time to wash their watches in fresh water after work, which caused dirt, silt, and salt residue to accumulate on the lock nut’s threads and make it difficult to unscrew or tighten it—which, let’s face it, isn’t good for timepieces at all.

It follows that our particular PloProf is not an outlier given the rate of attrition and the higher-than-average frequency of switching movements, dials, bezels, and even cases.

In the distant past, the dial and bezel were replaced. The dial has tritium markings and is a “D6” service dial. It is recognisable by the lume on the outer dial at 3 o’clock, which hits the date window, so it is obvious. The open loop 5 and flat-topped 4 of the “B1 Service B” bezel, which is what it is known as, make it easy to identify too.

The hands are “Variation 2” hands with the “extended lumen” hour hand. These were probably replaced at the same time as the dial and bezel, but we will never know.

The case is an Mk11 “Case 3”, with a “C”-shaped cutout for the crown and a metal, rather than plastic, lock nut. It looks lived-in, but so it should.

The watch is currently displayed on an Omega Milanese “Shark-Mesh” 1162 bracelet with 162 end links, which truly brings out the best in it. Initially, it would have been sold with either a black, blue, red, or yellow Isofrane rubber strap. Moreover, additional bracelet links are supplied with the watch, to make sure even the Incredible Hulk could put it on!

Overall, it just looks right.

The 1002 calibre movement within, has been serviced by our watchmaker and is running perfectly.

So, it’s ready for its next adventure; will that adventure be yours?

Thank you to for many of the technical details used here!

We work hard to ensure you are pleased with your purchase, both before and after the sale. Contact us to request any additional information.


We aim to dispatch items within 1-2 days receipt of payment.

The delivery method can vary depending on the value of the watch. All watches are sent fully insured usually using UPS.

All watches sold without an original box will still be dispatched with a high quality presentation box.


All timepieces purchased from us come with a guarantee of authenticity and our 12-month time-keeping warranty. Please note that accidental damage or damage to the item resulting from third-party repairs, improper handling, or liquid damage will void our warranty. We do not guarantee any of our watches to be waterproof.