With the motorsport season in full throttle, Summer is a busy time for TAG Heuer. Since the brand invented the brilliantly monikered 'Time of Trip' dashboard chronograph in 1911, it has clocked up the longest history in racetrack timing.

Currently gearing up for its role as official timekeeper of the Goodwood Festival of Speed in England at the end of this month, TAG has only just stepped off the timekeeper's podium at the US Indy 500 and the Monaco Grand Prix. To celebrate its long-standing association with the 'most glamorous Grand Prix in the World' and the famed Automobile Club de Monaco, it has just launched three new versions of the Monaco, one of the most recognisable watches - and product designs - of the early 1970s.

'In 1969, most watches were pretty small and round,' explains brand CEO Jean-Christophe Babin. 'Almost overnight Jack Heuer changed that by coming up with this new kind of chronograph. It was big. It was square and it was blue.' Even today, it looks completely different from any other watch design - it is instantly recognisable and still relevant.  

Less well known perhaps is the fact that the Monaco was the first waterproof square watch. 'Other brands had made square watches but they were not as bold,' says Babin. 'We came first with the patent, making a waterproof. This was a big step because all of a sudden it allowed square watches to become daily watches. If your watch is not properly sealed - and the waterproofness is a seal - you'll get condensation and, even worse, it will destroy and rust the movement. This is why we are so obsessed about watches being very waterproof.' To meet the technological criteria, the brand had to come up with ways of manufacturing the crystal (the glass that covers the dial) in a specific way too.

Of the three commemorative designs due to hit watch boutiques this month, our favourite is the Monaco Twenty Four. Inspired by the technology used to design racecars, vibrations are directed away from the movement into a filter that diffuses their energy. The go-faster racing suit stripes are a nifty touch too.