Synchron Poseidon

I’m going to start this review by saying that it is one I have already done. Yep, the Synchron Poseidon is very similar to the Synchron Military from 2021. However, the Military I reviewed was a prototype and I think there are enough differences to warrant a new review. To see what I wrote on the Military, head over to this page either before or after you read this.

Synchron Military

The first image should show you both the similarities and the differences.

Like the Military, the dimension of the watch are 42mm diameter (without the crown), 45mm lug to lug, and 14.6mm thick and it has a 300 meter water depth rating. The crown is signed with the Synchron logo, has an external thread stem tube and the case is recessed to allow the crown to screw into it rather than sitting flush with the case side. The watch head on its own weighs 51 grams. The 120 click bezel has a sapphire insert and unlike the Military which had countdown minute markings, the Poseidon has the normal 0 to 60 markings you would expect to find on a dive watch bezel. The crystal is flat Sapphire with an anti-reflection coating.

The hands on the new Synchron are different, with the Poseidon having a classic, large yellow minute sword hand. Then there is the dial. Yep, that is a Poseidon logo. So who exactly are Poseidon? Well who they are not is a watch seller / distributor / blogger / magazine etc, who seem to be the only people nowadays to have a tie in to a limited edition watch. I’m waiting for some Dive Watch company to release a Texas Farmers Daily Limited Edition. I’m glad to say that the Synchron Poseidon is a Limited Edition in conjunction with a renowned pioneer in the underwater world: Poseidon Diving Systems.

Just for the record. Poseidon are a Swedish company with a global footprint who were founded in 1958 by Ingvar Elfström with a quest to solve a range of diving-related problems. In 1958 they created the world’s first single hose regulator for the watersports industry. In 1963 they pioneered wetsuit zipper function. In 2008 they produced the first fully automatic rebreather and most recently they designed the first solid state oxygen sensor. Poseidon continues to lead the way with ground-breaking diving technology and specialized ideas that have shaped the industry. Their dive equipment is used by many of the world’s most demanding sport, professional and military divers. In the United States their regulators are consistently performing for the US Navy, the US Coastguard, NOAA and NASA on a daily basis. These guys are not the Texas Farmers Weekly.

But here’s where things get really interesting and this has been kept under wraps until now. Poseidon is the main supplier for all dive equipment to the Swedish armed forces and they were requested to supply a mechanical robust dive watch. Synchron and Poseidon joined forces to develop a military grade capable dive watch that will be tested above the polar circle end of January by the Swedish Armed Forces Colddivex 2023 edition. That watch is the Synchron Poseidon. There will be some minor tweaks to the watch on the inside and out, but those remain confidential as of now. What you are seeing here is the version of the watch that is available to the public.

One of the requirements for the Poseidon was that the watch have a longer power reserve than 38 hours. To achieve this Synchron chose La Joux-Perret and their G100 movement. The G100 was introduced in 2021. It is dimensional compatible to ETA 2824-2 and Sellita SW200-1 (25.6mm diameter, same dial feet positions and the hand sets will fit as the dimension of the Cannon Pinion are the same). The G100 in this watch is the highest grade available from LJP and is adjusted to 4 positions by LJP. It is hand wind and automatic, hacks, 24 Jewels, runs at 28,800bph and has an amazing 68 hour power reserve. It also has some innovations over the standard ETA 2824-2 and Sellita SW200-1. These include a rotor which is made from a solid piece of tungsten and turns on a ball-race held in place with 3 screws. Also a number of the wheels / cogs are made from CuBe (Beryllium Copper) and un-plated. The advantage of CuBe is that it work-hardens, is auto-lubricating and doesn’t tarnish. The shock protection for the balance pivots is made by Kiff, one of the two largest producers of shock protection in Switzerland. They were the shock protection supplier to Rolex until Rolex started making their own. You won’t be surprised when I say it is also considerably more expensive than the ETA or Sellita.

Well, if you think having the Poseidon logo on the dial is cool, then you need to check out the caseback. Not only is it wonderfully flat and allows the watch to sit lower on the wrist but it also has the Poseidon logo incorporated into it.

Unfortunately I just couldn’t get the lighting right to really show just how spectacular it is in real life so I cheated and used a bit of black card to highlight it. It’s a gobsmacker of a caseback. What I’m probably going to do is use black and yellow enamel paint to see if I can fill in the design elements and really bring it to life.

So what is the lume like? Everyone loves a lume shot, so see for yourself.

The luminous material is Super-Luminova and like any luminous material used since Tritium was banned for use on watches, it needs to be activated by light. The longer / stronger the UV content of the light, the brighter and longer lasting it will be. There is a lot of Luminous material on the Poseidon dial and hands so I think people will be happy with the night-time legibility.

The other thing about the dial is that whereas the Military was a light cream shade, the Poseidon is a very subtle shade of grey. It matches the supplied Isofrane rubber strap.

I received my watch well in advance of the public release. It literally came the way it is shown in the next image. Regular buyers will receive the watch with the Isofrane strap already attached in the Synchron Aluminum tube. Having to attach the strap myself allowed me to see the springbars, and I have to say they are some of the beefiest ones I’ve seen.

Adding the Isofrane was a breeze.

It matches the dial and looks great.

If you know me you know that I’m not a strap guy. Just can’t wear them. Within a short period of time, my wrist begins to itch and I’d end up with a rash. But for the sake of completeness here is a shot on my 6.75 inch wrist.

I even put it on an Aquastar grey Nato strap I have. I’m also sure it would look tremendous on a Tropic or one of Erika’s Originals straps.

The Isofrane was removed and in its place I added a bracelet that was pretty much made for this watch. It’s from a company called Suppaparts

It costs $115 and it comes with both faux Beads of Rice endpieces and ‘flat’ ones.

While the faux BOR endpieces are a great look…….

I prefer the flat ones.

When I said that this bracelet was pretty much made for this watch, well, there is a small caveat. It was made for a similar Tonneau case watch but it is not exactly the same. There is a slight misalignment of the springbar holes and case holes, so in order for the bracelet to fit you need to use thinner springbars. The bracelet I received came with thin springbars and they worked perfectly.

I know I have said before that BOR bracelets are as common as mud now. Every man and his dog seems to use them, but in this case, especially with the flat endpieces, it sure does look good.

The Suppaparts BOR bracelet also has the advantage that it is reversible. The underside is brushed so it compliments the flat endpieces.

Flat or brushed, they both look good.

Just as clarification in case people were thinking the dial on the Military looks more washed out than the Poseidon. It isn’t. The Military has a prototype bezel which has silver indices. When I use any kind of card to remove the crystal reflections it just blacks out the Military indices. This is what both dials look like in a real comparison.

So how does the Poseidon look compared to other watches. Here’s a selection of photos with it beside some watches I own.

Marei Era DOXA SUB 1200T Diving With Legends

Seiko Black Monster

Aquastar Deepstar 39mm

Rolex Sea-Dweller

Aquastar Deepstar II

Aquastar Benthos H1….. Wait, what, say that again. What the heck is the Aquastar Benthos H1? Where did that come from? It’s a prototype which almost got released, but it is now sitting in the shadows waiting for its big brother to appear. You never know, it may see the light someday. That Rick Marei guy has been busy!

From the top: Deepstar 39, DOXA SUB 1200, Poseidon, Benthos H1.

OK, so is there anything I don’t like about the watch? Well, to be honest, there is nothing I really don’t like but there are 2 things I would have changed. The first is really just cosmetic. I would have polished the bottom part of the bezel. Take a look at the next photo. The part of the bezel below the teeth looks beadblasted to me. It doesn’t match the brushed finish of the case. If it had been polished there would have been symmetry either side of the case with the polished caseback edge. Most people would never notice nor care, but I do and my preference would have been to polish the whole bezel.

The other thing, and this really is just my preference, would have been to profile the side of the case so that the bottom part of it had roughly the same arc as the top. The Synchrom Military and now Poseidon are based on the 3rd generation vintage Synchron Tonneau case. It was the thickest. The first and second were slightly thinner and had side profiles with a bottom curve. I just prefer the look of those. But I’m probably in the minority.

There really isn’t much more to say. The Synchron Poseidon wears just like the Synchron Military. No real surprise there, but it really is a different watch on the wrist. I’m a sucker for logos on dials and in my case the Diving With Legends logo is the best. You knew I’d say that, but the yellow Poseidon logo on the Synchron comes a close second and tells you that if someone of the caliber of Poseidon Diving Systems are happy to be associated with the watch, then maybe you will be too.

The Poseidon really is a tremendous addition to the Synchron stable and it bodes well for the future. It’s limited to 1000 pieces and there will be an option of white hour and seconds hands during the order process. I have not seen the version with these hands so could not post any pictures. The Synchron Poseidon is available for $990 from SYNCHRON USA