Ressence Type 5G Grey

Quick specs Ressence Type 5G Grey
Price: € 31.500 | approx. $ 34,400 | approx. £ 23,900
Size: 46 mm
Reference: TYPE 5G

This is a strange yet interesting time piece. In order to keep the dial of this Ressence Type 5G Grey perfectly readable under water from any angle it is filled with oil. The oil eliminates the phenomenon called Total Internal Reflection. When you look at a traditional diving watch if you are under water you have to look in the right angle to read it. If you change the angle a little you will get refraction which turns the glass into a mirror. But not with oil just under the glass.

The Ressence Type 5G Grey features an ETA caliber 2824-2 which has been modified by Ressence. On top of it is the Ressence ROCS 5 module driven by the minute axle of the customized ETA caliber 2824. Between the module and the front glass, with the dial in between, there is 37.5 milliliters of oil. As a liquid like oil cannot be compressed it compensates the pressure under water. And therefor there is no need to have an over-sized case or thicker glass.

Besides that, the oil constantly lubricates the ROCS 5 module. And as all the 142 components of the module are suspended in liquid the components are lighter than regular components. And lighter components require less power to move. Now if the temperature rises or falls the volume of oil will expand or diminish. For that, Ressence has developed a system with seven small bellows that retreat the oil when it expands under the effect of heat. And it compensates the contraction of the oil under the effect of cooling. All in a range of -10 to +60 degrees Celsius (14°F to 140°F) without affecting the correct operation of the watch.

The module of the Ressence Type 5G Grey is separated from the base movement

The ROCS module of the Ressence Type 5G Grey is hermetically separated from the automatic base movement by a titanium membrane. So, no oil is leaking into the base movement. The connection is realized by magnetic transmission: micro magnets on either side of the membrane. In case of significant lateral shocks these magnets can momentarily decouple but a hydraulic shock absorber compensates this. If you really want to know, the hydraulic shock absorber is a small disc with blades that is integrated with the ROCS module.

When there is a shock, the blades start turning very quickly, like a turbine, and suck in the oil while the oil can only escape by microscopic spaces. That process slows down the ROCS module which (somehow) prevents disconnection from the base movement. The shock absorber is manifested visually by the rapid rotation of the runner disc integrated in the dial.

When you understand the tech of the Ressence Type 5G Grey you still need to get used to how to read the time

Overwhelming? It is. There is a lot of tech in this watch, a lot of complicated systems to have some drops of oil under the glass. Just to make it readable under any angle when diving. And then you still have to figure out how the time is displayed. Hang on, we will explain how that works. The outer ring showing the minutes isn’t moving: the main disc (which is the whole dial) moves.

A large ‘hand’ drawn on the main disc points to the outer ring to show the minutes. Within the main disc there are three eccentric bi-axial satellites or sub-dials. These are for the other functions, and each has a stationary ring for the indexes or markers. And they change position by the minute as the main dial turns by the minute.

You can even read the oil temperature

Now, the biggest sub-dial with the Ressence hand logo shows the hours. The small one with the blue, yellow and red index shows the oil temperature while the other small one shows the rotation of the shock absorber. But as these sub-dials are on the rotating main dial every time you want to read them, they are at another position.

It’s an unorthodox way to show the time and let’s hope you will get used to that when you buy one. And if you are not into grey, there is also a version with a black dial and titanium case. Or a version with a black dial and black DLC case. All at the same price. Which is high, but considering the techniques, less overwhelming.