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Omega Seamaster Planet Ocean 

A great diver’s watch

Review of Omega Seamaster Planet Ocean

The Planet Ocean is available in both a black version and a version with an orange rotating bezel and orange numbers on the dial. Furthermore, you can choose between a 42 mm and a 45.5mm case.

The Planet Ocean is newest member of the Omega Seamaster family. It is a great diver’s watch with an interesting movement and a classic design.

The first time you get a chance to see the new Planet Ocean up close, it will not take you long to recognise the Omega design.

The case has the same features, as you will find on the classic Speedmaster, although the diameter is quite a bit larger. The model we received from Swatch Group Nordic had a case diameter of impressing 45.5 mm. The so-called ‘oversized’ watches are gaining in popularity these years. This trend is also reflected in the Planet Ocean models that only are available in 42 and 45.5 mm.

The design of the hands is not new and has been seen on several previous Omega models – latest the Broad Arrow.

However, this time it is not only the minute hand, but also the hour hand that has an arrow-shaped look.

The design of the numbers on the dial also brings back memories from Omega classics.

Generally, we see the Planet Ocean design as a very classical and successful one. Nevertheless, it is possible to get a Planet Ocean with a more modern look, should some prefer that.

The watch is also available in a version with an orange rotating bezel and orange numbers on the dial. Furthermore, this version comes with an orange alligator-skin strap, which gives the watch a look that no one can regard as boring.

The orange colour has been chosen because it, according to Omega, is one of the most visible under water. It is possible to get both the orange and the black version of the Planet Ocean with a stainless steel bracelet and a rubber strap. As mentioned before the orange version comes with an orange alligator-skin strap whereas the black version comes with a dark brown alligator-skin strap. This gives the customer several possibilities to customise his watch and helps widen the target group. The black version can, with either a bracelet or an alligator-skin strap, easily be worn as a dress watch. With the rubber strap, it looks more like an everyday-watch that is made to be used – also for diving. Though it is probably a minority of the watches that will ever see anything deeper that a bathtub.

The orange version is probably targeted towards the female and younger segment with its very modern look. Orange is a colour that is becoming more and more popular on watches, especially diver’s watches. Two years ago, Rolex presented the 50th anniversary version of the Submariner with a green rotating bezel and now with the Planet Ocean there are two well-made diver’s watches on the market with bright coloured rotating bezels. We will probably see more of this trend from other watch companies in the future.

The general impression of the quality is good and the care of details does not leave anything behind, exactly as we know it from other of Omegas models. The tested model had a rubber strap, which was very comfortable to wear. The stainless steel bracelet has a sateen-like surface and the well-known Seamaster folding clasp. This is a very well-made and robust folding clasp that is opened by pressing two buttons, which makes opening the claps by accident a very rare phenomenon.

The movement is an Omega calibre 2500, which is a greatly modified ETA 2892-A2. The movement has co-axial escapement, which is also known from the DeVille and Seamaster Aqua Terra models. According to Omega, the co-axial escapement reduces the friction in the movement and thereby offers much better long-term reliability and accuracy. In the very popular Omega Seamaster 300 M Diver Chronometer (know from the 007 movies) is a calibre 1120 which is based on the same ebauche from ETA, but the 1120 caliber does not have the co-axial escapement. This is the main difference between the two movements.

It normally takes a larger than average wrist to wear a watch with a diameter of 45.5 mm, but it helps significantly if the lugs are downward-curving. This is not the case with the Planet Ocean and it therefore makes quite high demands on the wearer’s wrist size. With the very well-designed dial, the watch is easy readable in daylight as well as in darkness – an important feature for a diver’s watch. The Planet Ocean is definitely above average here.

The rotating bezel is, due to the grooves on the edge, easy to rotate. This is clearly an improvement compared to the rotating bezel on the Seamaster 300 M Diver which could be quite hard to work correctly. The overall quality of the Planet Ocean is compared to the Seamaster 300 M Diver Chronometer a level higher. When the quality goes up so does the price and this is also the case with the Planet Ocean that retails for almost 50 percent more that the Seamaster 300 M Diver Chronometer.

As mentioned earlier, the Planet Ocean is available in a 42 and 45.5 mm version. It is a shame, by our opinion, that you cannot get a smaller version - for example a 39 mm. There is no doubt that oversized watches are very in these days but not everyone is equipped with a Sly-sized wrist. Moreover, who says the oversized watch trend will last? We see this as the only major minus and therefore rate the Planet Ocean as a four on a scale of one to five.



The design of the Planet Ocean is classical and very successful. This combined with the alternative of a black or orange version and the choice of stainless steel bracelet, rubber or alligator-skin strap gives a very wide target group. This target group could, by our opinion, be extended further if a 39 mm version was available.


Helium escape valve

Why is there a helium escape valve in a professional diver’s watch?

When commercial deep-sea divers operate on great depth, they work from a diving bell. A diving bell is a cable suspended watertight chamber used for underwater work. It has a lid in the floor and is supplied with compressed air. Using the diving bell a small number of divers can be lowered into the water. Once they have reached their work site they use the diving bell as a base. While working at the depth they can return to the diving bell to eat and rest.

When the diving bell is lowered into the water and pressure in the bell increases, helium is added to the breathing mix. This is done to remove nitrogen and reduce the percentage of oxygen to below that of air, and thereby allow the mix to be breathed safely at greater depth. It is not safe to breathe atmospheric air (which contains 78% nitrogen and 21% oxygen) at great depth, because the nitrogen becomes narcotic and the relatively high percentage of oxygen becomes toxic as pressure from depth increases.

The divers continue to breathe the helium/oxygen mix while working at the depth. At their returning to the surface, the pressure in the bell is maintained. The diving bell is locked onto a decompression chamber when reaching the surface. The pressure in the decompression chamber is then equalised to the pressure in the bell and the divers move from the bell to the chamber. They then go through a decompression routine that can take several days.

Prior to this decompression routine the divers have been in the highly helium saturated atmosphere for an extended period. Because helium is such a small molecule, it will seep through the watch’s seals under the high pressure in the bell. If the watch stays in the helium-saturated atmosphere for extended period, then helium will continue to seep into the watch until the air pressure inside the watch, equalise to the air pressure in the environment.

While the helium seeped into the watch over an extended period, it cannot seep out any faster. The pressure in the decompression chamber decreases faster than the helium can escape the watch and this can make the crystal on the watch pop out during the return to atmospheric air pressure. To avoid the crystal from popping out the professional diver’s watches have a helium escape valve. The idea is that the helium can escape through the valve as the pressure in the decompression chamber decreases.

How does the helium escape valve work?

The purpose of the figures below is to illustrate the concept of the two most common types of helium escape valves used today. Several watch companies uses these kinds of helium valves. The first one is best know from Omega Seamaster and the second one from Rolex Seadweller.

This is the kind of helium escape valve you will find in a Omega Seamaster. Simply unscrew the crown to open the valve. The watch is still water-resistant when the valve is open.

Please note that the right picture, above this text, shows the open helium escape valve exactly the moment when the helium escapes the watch..

Rolex uses this kind of helium escape valve in their Seadweller. This valve works automatically and opens when the pressure inside the watch is much greater than pressure outside.

Please note that the right picture, above this text, shows the open helium escape valve exactly the moment when the helium escapes the watch.

Last but certainly not least, we would like to thank Ariel Zlotnik, Swatch Group Nordic for making this review possible by lending Watchlife.com the watch.

Use the Store Locator on the official Omega site to find an authorised Omega retailer in your vicinity - please click here

If you have any comments or questions – please send an email to Tais Brüniche-Olsen at tbo@watchlife.com

Tais Brüniche-Olsen & Lau Brüniche-Olsen