The IWC Aquatimer, ref. 3536-003, has a storied history despite being a modern wristwatch. It represents the triumphant reissue of the classic Aquatimer line, which was launched in 1967 with the Reference 1815. The Reference 1815 was IWC's first attempt at a dive watch, released in an era when IWC had tough competition from Rolex (with the ) and Blancpain (with the ). 

At the time, IWC was known mainly for its pilot's watches, epitomized by the . Despite the fierce rivalry between Rolex and Blancpain to develop a dive watch, IWC seemed resistant to the trend. With the Fifty Fathom's association with Jacques Cousteau, and the Submariner's as-then unsurpassed depth rating of 200m, there seemed little room for improvement in dive watches. 

But IWC quietly developed a prototype of the watch that would become the Aquatimer in 1964. The first reference of Aquatimer available for retail, the ref. 1815, was released in 1967. It featured the same automatic movement that was used in the Ingenieur, the cal. 8542. In appearance the Aquatimer owed much to the Ingeniuer, with a similar dial and bracelet. However, the Aquatimer, to suit the depths that it would descend to, had a thicker crystal and case with a patented sealing technology and a rotating inner bezel.  

Despite the poor performance of the ref. 1815's successor, the 1816, and the encroaching Japanese Quartz technology, IWC continued to develop new models of Aquatimer. The most iconic model of Aquatimer from this period was the Ocean 2000. Designed in concert with Ferdinand A. Porsche in 1978 and released in 1982, the Ocean 2000 was IWC's answer to the hot new styles of quartz watches: a mechanical watch with an unusual, distinctive case completely different from the iconic Gerald Genta design of the Ingenieur. The Ocean 2000 was developed for the German Bundeswehr (like the Heuer pilot's watch that carried the same as the German army) and was the first dive watch to have a case made of titanium. This reference revitalized a foundering line and was its benchmark until the release of the GST Aquatimer in 1997.

The GST Aquatimer (ref. 3536) is IWC's answer to the notion of a "professional dive watch" posed by later references of the Rolex Submariner. It combines a classic round case (sturdy, of course) with an elegant dial with distinct Bauhaus influences. Yet lest its appearance deceive you, the GST Aquatimer took the watch to a depth of 2000m. 

The ref. 3536 was available in stainless steel with a black dial (ref. 3536-002), titanium like the Ocean 2000 (ref. 3536-001), and in stainless steel with a white dial (ref. 3536-003). Ours is an example of the latter reference, which only saw a release of 6000 pieces, making it quite rare. Another interesting feature is the luminescent material on the markers and hands: tritium, which was only produced until 2000, when the brand (like so many others) switched to SuperLuminova. What results is a dive watch that's the perfect alternative to the Rolex Submariner. While imposing on a bracelet, its sturdy build and clean, legible dial make this piece an eye-catching sport diver.