It must be one of the most well-worn words in horology, but what, exactly, is a “tourbillon” watch? The idea of a tourbillon is to counter gravity’s effect on a watch escapement, that part of the mechanism designed to transfer the power of the mainspring to the going train.

Ideally, this happens in a smooth, linear and constant fashion – but it was soon discovered that pocket watches suffer from loss of accuracy if they spend extended periods in the vertical position (ie in a waistcoat pocket), because the escapement’s constant battle against gravity causes erratic power delivery. A tourbillon solves this by housing the escapement within an exquisitely crafted cage that turns on vertical and horizontal planes, preventing it from spending a significant length of time in the same position.

First to conceive the mechanism was John Arnold, but he died in 1799 without bringing the idea to fruition. It is now commonly associated with his friend Abraham-Louis Breguet, who patented the idea two years later, respectfully fitting his first fully operational tourbillon into an Arnold pocket chronometer, which he gifted to Arnold’s son. Breguet’s name remains synonymous with the mechanism that is regarded by many collectors as the ultimate expression of the watchmaker’s art.

The modern-day Breguet brand (owned by Swatch Group since 1999) furthers this legacy by occasionally introducing new tourbillon watches, one of the latest being the Reference 5577, which contains the difficult-to-produce tourbillon mechanism within a case measuring just 9.35mm thick. It is the first time Breguet has fitted this mechanism to a model from its Marine range.

Among his many achievements, Breguet was appointed chronometer maker to the French Royal Navy in 1815. Vital for accurate calculation of longitude on the oceans, a marine chronometer was long regarded as an essential piece of operational equipment for any significant voyage.

Today’s Marine line pays homage to this historical association, combining the heritage of high-seas chronometry with that of the tourbillon. It works well in the Reference 5577, which doesn’t ignore modernity for the sake of tradition, notably employing silicon in the escapement and hairspring for its low friction and long life.

Elsewhere, the watch is rich in unusual details and exceptional finishing, recalling the observation once made by Breguet authority, the late Sir David Salomons, that ‘to carry a fine Breguet watch is to feel that you have the brains of a genius in your pocket’.

The dial and hands are offset rather than being conventionally centralised, the tourbillon displayed through an aperture in the space between four and six o’clock. The “sunburst” finish of the dial is made in slate grey (for rose gold watches) or blue (for platinum), both of which feature a sapphire crystal caseback that gives a view on to the beautifully decorated movement.

There, you’ll find maritime imagery such as the compass rose and ropework engraved on the top of the mainspring barrel, a mainplate striped to resemble deck planks and a wave pattern gracing the platinum peripheral rotor. The nautical theme extends to the strap, too, with a clasp based on the look of a ship’s wheel.

Despite the highly decorative appearance of the watch, it’s water resistant down to an impressive 100 metres. Although, at £152,200 for platinum versions and £138,200 for rose gold, wearing one while going for a plunge isn’t recommended.

breguet.com