IWC Aquatimer Deep Two IW354703

Safety counts

Aquatimer Deep Two

The Aquatimer Deep Two, the diver’s watch with a mechanical depth gauge is once again on board. It has everything a diver needs for his safety.

Divers not only immerse themselves in a fascinat ing foreign element, but also place themselves in the hands of technology. Dive depth, dive duration, rate of ascent and descent, decompression stops – everything must be exactly right to ensure that a breathtakingly beautiful adventure does not turn into a nightmare. Fortunately, there are now computers to relieve the diver of most of the calculations. Yet divers, like parachutists, encounter a similar situation: If one could be quite certain that the system would always function under all circumstances, there would be no need for a reserve parachute. As far as diving is concerned, this is where the built-in safeguard of the Aquatimer Deep Two takes over, the second diver’s watch from IWC with a mechanical depth gauge and a maximum dive depth indicator. It offers a complete backup system if the electronics of the dive computer were ever to fail.

Both technically and in terms of its dimensions, the Aquatimer Deep Two diver’s watch is the hero product of the new Aquatimer generation from IWC. It acts as a reliable reserve, which permits the dive time to be read off the distinctive external rotating bezel. This is true under all conditions of visibility, incidentally, because the bezel conceals a highly concentrated dose of Super-LumiNova® luminous pigment beneath the 4-mm wide sapphire crystal ring. This functionally very important detail also gives the entire Aquatimer family its new face. The new external rotating bezel was also developed to provide increased user convenience.

Yet the Aquatimer Deep Two only becomes a complete backup safety system with the second important parameter when diving, namely the dive depth, and in particular the greatest depth reached during a specific dive. With these two values, an experienced diver can plan the essential decompression stops at any time during the ascent and remain at the correct depth in order to complete the dive unscathed. The maximum rate of ascent of 10 metres per minute can also be accurately controlled with the help of the seconds hand and depth gauge. Safety counts.

Housed inside the stainless steel case of the Aquatimer Deep Two with a diameter of 46mm and a height of15.5mm is a reliable 30110 calibre automatic movement with central seconds hand, date and a 40 hour power reserve. Its true speciality – measuring dive depths – is functionally completely separate from and unaffected by the movement. In plain language: the depth gauge itself would continue to function even if the movement were to stop. In the technical realization of the mechanical depth gauge, the engineers drew on knowledge gained from the construction of the GST Deep One diver’s watch precisely ten years ago, although they explored new avenues with regard to the depth-gauge sensor for detecting the underwater pressure.

The GST Deep One was equipped with a measuring tube arranged internally around the movement, which filled with water via micro bores in a crown during the dive, was caused to deflect as the water pressure increased and in so doing transmitted the ambient pressure via a lever mechanism to a flyback hand. The arbors of the measurement hands passed centrally through the movement in this design. It was capable of measuring depths of up to 45 metres.

In the Aquatimer Deep Two, on the other hand, the engineers at IWC have opted for an entirely new approach. The watch has a semi-circular indicator for water depths on the left half of the dial. The actual dive depth and the maximum depth are indicated by two hand tips in blue and red. The pressure measurement system of the Aquatimer Deep Two is contained in a second crown provided with a cover, which is also located on the left – the protected – side of the case. When out of the water, the pressure transducer is set to “Depth zero”, that is to say normal atmospheric pressure. The water pressure acts via micro bores in the cover of the crown against a sprung and mechanically guided membrane and forces a pin into the interior of the case. This precisely defined movement actuates a lever mechanism situated just beneath the rotor, directly behind the case back, and causes the two measurement hands to de flect via a train of gears.

The largest part of the two depth measurement hands remains invisible from the outside, however. Only the raised tips of the hands at the level of the dial look out from a semi-circular slot in the dial and move over the indicator scale. The hands in this case are led around the movement.

This is an ingenious solution, which avoids the need for the path of the arbors to pass centrally through the movement. The depth indicator (blue) moves over the white measuring field de pending on the actual depth of water at the time. The maximum depth indicator (red) always remains at the greatest depth reached. It is, in fact, mounted on a wheel with special teeth, into which a pawl engages and arrests the wheel after every additional partial movement (in the direction of greater depth). The pawl can only be released by a button underneath the depth-gauge sensor crown on the left side of the case. The maximum depth indicator then returns to the position of the depth indicator by spring force. This is a very reliable system.

The spring-assisted pressure transducer comes up against its stop when a depth of 50 metres is indicated. Purely theoretically, it would be possible to dive even deeper with this watch, which is pressure-resistant to 12 bar, although the actual depth is then no longer shown. The recommended maximum depth for scuba divers should not exceed 40 metres in any case. The crown with the depth-gauge sensor has an additional function: it can be rotated to permit accurate calibration of the two hands of the depth gauge. The cover over the sensor crown, which is secured to a hinge and snapped into engagement, can be flipped open to clean the system if the need arises.