One of the things I love about wristwatches is that they teach you so much about the fundamental aspects of time, our planet and the strange oddities that occur in our timekeeping methodology when the real world doesn’t nicely coincide with a practical system. Perhaps the best known example of the latter is the leap year, where we cram all the extra time that’s supposed to be around the edges of our days and years into a single extra day every four years. The Breguet Marine Tourbillon Equation Marchante 5887 is dedicated to a different such phenomenon.
Specifically, the Breguet Marine Tourbillon Equation Marchante 5887 is a grand complication watch that combines a perpetual calendar and tourbillon with the much rarer equation marchante complication. This function allows the watch to display both ‘mean solar time’ and ‘real solar time’ simultaneously. The easiest way to understand the difference between mean and real solar time is that mean time is the standardised time we live our day to day life by – that’s partly the reason GMT stands for Greenwich Mean Time. Meanwhile, real solar time is the true local time based on the position of the sun in relation to the Earth.
For example, a wristwatch typically displays mean solar time but a sun dial displays real solar time. However, if you compare your wristwatch to a sun dial every day at the same time for a whole year, you’ll discover that the time according to the sun dial goes out of synch by up to as much as 16 minutes faster or slower than your watch. That’s because the Earth’s orbit is not perfectly circular and the planet is on a tilted axis, meaning real solar time can vary quite considerably depending on the time of year. Mean solar time is derived from the average of these discrepancies, hence mean.
Breguet’s equation marchante complication has two hands, a regular minute hand that displays mean solar time and a second minute hand equipped with a golden disc as its tip that displays real solar time. It’s a fascinating insight into the operation of our world and the systems humans have created in order to understand and control it. Similar in some regards to the IWC Eternal Calendar, which is an extreme version of a perpetual calendar accurate until the year 4000 and even then we can only say that it might not be accurate because humanity hasn’t yet decided if the year 4000 will be a leap year.
So far this has been a pretty intense article on scientific concepts so let’s zoom out and talk about the design of the watch for a moment. It has a 43.9mm diameter platinum case similar to the original Marine Tourbillon Equation Marchante that Breguet released in 2017. However, where the original had an ultramarine blue dial, this new edition has a black dial, giving is a much more sombre and sophisticated appearance. I’ve always been a fan of monochromatic design and the contrast between the dark wave motif guilloché and the bright silver tone of the hour scale and platinum case is very satisfying. Especially as it really emphasises the golden equation marchante hand.
The watch’s perpetual calendar complications are found via the days of the week window at 10:30, months at 01:30 and retrograde date scale nestled inside the hour scale with an anchor-tipped hand. At 5 o’clock is the characteristic tourbillon, a mechanism first developed by Breguet’s influential watchmaking founder, Abraham-Louis Breguet. Lastly, between 7 and 8 o’clock is a power reserve indicator.
The power reserve of the movement is 80-hours, provided by the calibre 581DPE. It’s an automatic movement with a peripheral rotor, visible through the exhibition caseback. Aesthetically it’s one of the most stunning movements around finished with immaculate engraving that depicts the Royal Louis warship from 1752 alongside a compass rose.
As for price, well, between the platinum case and the grand complication movement it’s not what you’d describe as accessible. In fact, this watch makes timepieces like the Panerai Perpetual Calendar GMT look accessible by comparison and that watch is 30k. Without beating around the bush any further, the Breguet Marine Tourbillon Equation Marchante 5887 is a cool £253,300.
Price and Specs:
More details at Breguet.
