The Rolex Seadweller has a long history. It is not the best known Rolex, but it has plenty of followers. For many people it is just the right heft and presence on the wrist.

The first mass produced Seadweller was unveiled in 1967 (here is my write-up about the 1665, the first SD) and was meant as an augmentation of the Submariner, that was initially unveiled a bit more than ten years previously. The sub was plenty good enough for diving with 200m water resistance, but it turned out that divers were reporting that sometimes, in the decompression chamber, the crystal would pop off. Therefore, Rolex decided some sort of a solution was in order and they came up with the concept of the gas escape valve (I wrote a bit about it here, to avoid explosive decompression.

Here is a photo of the genuine 16660, the second gen Seadweller, before the 16600, and after the 1665, double red. It is worth about $50K at the moment. Notice the COMEX logo on the dial?

I cannot recall if I ever previously mentioned COMEX (Compagnie Maritime d’Expertises)? COMEX is a diving company, focusing on extreme depths diving, military applications and off shore drilling platforms. At its inception, they were the only serious diving company in the world, and evolved into an international enterprise, with thousands of employees and strong research and development department. At its height COMEX approached Rolex and asked them to develop precision diving instruments for them. Through this collaboration the Helium escape Valve (HeV) was developed and Rolex committed to branding some of its watches with the COMEX logo. If you have the time, read this account of what being a COMEX driver in the seventies was like. Anyway, back to this write-up.

Some time ago, I came across an advert for a rep Rolex Seadweller case without a crown, bracelet or insert. The advert was not clear whether this was the second generation (16660) or the third generation (16600). It is probably the third, because the second generation still had the bracelet pin holes drilled through and through. The price was reasonable and I managed to get it down a bit. So I ordered it. Notice how it has a similar bezel mechanism to the five digit submariners, but not like the newer ones.

You can see the HeV quite clearly here, on one side.

This is, reportedly a BP Factory v1 case. I previously reported on 1665 double red sea dweller and this one is two generations later, I believe.

No matter. Yuki (I am now listing their name as they recently went out of business, so they can’t be sued for copyright infringement any more. Hong Kong, man) is selling a 16660 (i.e. 2nd gen) COMEX dial with hands. This is almost certainly a mix-up, since the second gen dial does not have raised indices and this one does. Also, the dial has 3135 feet positions and hands dimensions, although the 16660 initially came with the 3035 feet positions, which are not the same, if I recall correctly. Ironically, this dial cost me more than the case, and even more than the movement. I would have preferred a non COMEX marked dial, but they don’t have one. So, that is what I ordered from Hong Kong.

This is quite high quality dial. Most rep dials are not machined that well. It is however, almost certainly not a Singer, which Rolex actually used from time to time in those times.

I am missing, at this point, the movement, bracelet, insert and crown. Crown is easy. I have several rep crowns with our without tubes in my parts drawers.

I tend not to go for genuine Rolex parts, as they are prohibitively expensive. With Omega, I am happy to go genuine, quite often, but those parts are not that expensive, comparatively. I am not saying Rolex parts aren’t worth it. I personally just do not see the point. I would rather buy a genuine watch, than spend thousands of dollars on a watch that is still just a high end toy in the end.

The movement is also somewhat easy. I have two 3135 working movements. One is an old AS3135, which I’ve gotten in the Noob v7 sub, I bought months previously. It was in need of a service and regulation, so I bought an additional broken AS3135 for peanuts (like 20 bucks or so), cleaned the first one and replaced the parts that broke during servicing and oiling. And some did break. I swear, the Chinese make some of the parts out of candy floss, it seems. I ended up with one fully serviced and regulated AS3135.

I also have a spare VR3135 – I used to have 3 but a part of one broke during use and I haven’t gotten around to replacing it, as the genuine Rolex part (which fits) costs more than the whole VR movement, and spares for the VR are rare. I might buy another movement, but right now, I have no need. I used the VR.

In the photo above you see SH3135 on the left (an early replica of a 3135), a genuine Rolex 3135 on top and the VR3135 on the right. A nice finish and very well crafted.

I now need a bracelet and an insert. I have plenty of submariner bracelets and various clasps. For purists this is of course a total blasphemy but as long as the SEL’s fit well enough, I am not complaining. And they do.

In the photo above you can see that I also procured a bezel insert too. None of the submariner inserts fit. The crystal is a fraction of a millimetre too wide. So I had to order 16600 insert and because I balk at paying hundreds of euros for a piece of metal or ceramic, I could only find one Italian seller who was selling replica metal 16600 inserts for a reasonable price. No one was selling ceramic Seadweller inserts at all, let alone replica inserts, at the time. The insert situation is a bit bizarre with the 16600. The same serial number 3rd gen SeaDweller was updated with a ceramic insert at one time, so either metal or ceramic would work, just depends on when you buy it. The genuine ones have the insert replaced at service time, probably. Rolex does this shit, reportedly – they simply replace parts for newer ones, although this sometimes drastically lowers the price of the watch. The insert did not fit perfectly, so I had to sand it down a bit.

There are scratches on the case and insert. Well, why shouldn’t there be? This is meant to be a tool watch, several decades old. It would get scratched.

Anyway. I fitted the hands and dial, found a crown that fit the tube, tested for water resistance, which it passed. I have the Rolex tube removal tool too and several tubes, so I could go that way too, if need be. But, there wasn’t a need this time. It certainly has a 7mm crown as the subs do. So it is 703 or 704 that would fit. I just used a sub crown, no one without a loupe would notice the difference. I wore the watch for a bit, but then noticed that hands were out of alignment.

See? When it is half eleven on the clock, the hour hand should be exactly between 11 and 12. Here the hour hand is more like at 11:10 or 11:15.

The hour hand should be at eleven exactly. Clearly this needs fixing. So back to the drawing board.

Open it up. Uses the same opener die size as the modern ceramic submariner.

The VR3135 in all its glory. It is not clearly visible here, but the movement is slightly smaller than the case and no movement rings that I have, will fit. It is less than a millimetre on all sides. Just enough to dance around. The Rolex 3135 is, of course, larger diameter (28.5mm) than ETA 28xx (25.60mm). The stem height is also different. The seller of my case did not specify whether it was an ETA or Rolex case, but my dial and hands are Rolex 3135, so I attempted to fit them in. And they did fit.

The movement is out and I need to re-set the hands. For that I use a microscope, which makes it a lot easier. I recently bought a cheap digital one in order to take fancy photos for this blog. I use an old school mechanical one for work, though.

I need to align the hour hand perfectly. It is pretty well done here. Then I put in the minutes hand.

I only need to fit in the seconds hand. This is quite fiddly. What I do nowadays, after some trial and error through years, is to put the movement in the holder sideways and use a fitter with some rodico on the end to which I attach the seconds hand. I use the microscope to fit the seconds hand on the protruding seconds wheel. Cannot show you this in more detail, as both of my hands are busy then :).

Seconds hand is fitted and clearances look good. Put the movement back in and close it up. Here is the final product.

The 166600 is on the right, on the left is the 116600LN Noob v7 with a genuine xtal and VR3135 inside.

On my hand.

I am quite happy with how it turned out. The only thing I would change is the insert to a ceramic one. If I find a rep one, I’ll swap. But until then, I am ok with how it is now.