A Voyage Between Sky and Sea: Breguet Marine Hora Mundi 5555

Breguet marks its 250th anniversary with the fifth chapter in a series of exceptional timepieces: the Marine Hora Mundi 5555, a limited edition of just 50 pieces. Inspired by NASA’s “Black Marble” – the view of Earth at night from space – the watch celebrates the world in motion. City lights shine across the dial, a poetic nod to its spirit of traveling. For the first time, the Marine Hora Mundi is offered in Breguet Gold and decorated with a new phosphorescent enamel dial, a technique under patent. Collectors can even personalize the cities assigned to each of the 24 time zones, making each watch a unique creation. 

Two Superimposed Dials

The commemoration watch builds on the existing Marine Hora Mundi: a 43.9mm-sized case and the sophisticated 77F1 caliber, offering two time zones with day/night indication and a pre- programmable instant jump dual time zone. However, the dial is entirely new. Its deep, rounded effect comes from two layers. The base is a gold dial with a gradient from sky blue to navy, with the meridians and parallels that create a curved Earth illusion being hand-guilloched. While being flat, the illusion is being created by the lines converging towards the four cardinal points. This optical work provides the first component of the dial. Above it, a translucent sapphire dial adds even more depth, creating the sensation of observing the Earth from space.

Tradition Meets Innovation in Enamel

This dial is entirely hand-painted in three stages, on both sides of the sapphire crystal. First, the continents are painted in miniature enamel on the back of the crystal. Because the sapphire is flat, the outlines of the continents are extended toward the edge using a transparent petit feu enamel applied by pad printing. The craftsmen then fill in these contours with enamel. This step is particularly demanding: the continents must be painted in reverse, like a mirror image, so they appear correctly when viewed from the front. Once complete, the enamel is fired at high temperature to set the design.

Next, the artisans turn the sapphire crystal around and paint clouds on the front. This second layer, also created in enamel, is fired once again at a very high temperature. While the continents remain fixed, the clouds are left to the artist’s imagination. They drift freely across the oceans, giving each dial its own atmosphere. This means no two Hora Mundi 5555 watches will ever be exactly alike, each one carries a unique interplay of land, sea, and sky.

Finally, the cities that glow at night are added. Instead of the more common Super-LumiNova, Breguet uses a rare technique: tiny applications of phosphorescent enamel. This gives the map a magical effect, as if the world itself were gently illuminated after dark.

At the core of the Marine Hora Mundi 5555 is the caliber 77F1, a self-winding movement designed to make switching between time zones effortless. First introduced as the 77F0 and updated in 2022, it not only displays the time and date but also a second time and date tied to one of 24 world cities. Its secret lies in a patented mechanical memory system. After setting the first city with the crown at 3 o’clock, the second can be programmed with the pusher at 8 o’clock. A press of that pusher instantly switches between the two, with the time and date adjusting automatically. A small display at 4 o’clock shows whether it is day or night in the chosen city. This ingenious mechanism, protected by multiple patents, is unique to Breguet and remains unmatched in the world of mechanical watchmaking. It goes without saying that the 77F1, which offers a power reserve of 55 hours and is equipped with a silicon balance spring, is finished to the highest haute-horlogerie standards. In this edition, its oscillating weight inspired by a boat helm is crafted from Breguet Gold.