The Zenith Chronomaster El Primero Grande Date Full Open reveals the application of Jean-Claude Biver’s marketing approach as already applied at Hublot. There, a single in-house movement, the Unico, has been used for countless skeletonized Big Bang variants. At Zenith, Biver already had a legendary movement, El Primero, and so this year he opened up the dial in several fully skeletonized versions. The new Chronomaster El Primero is different to previous Chronomaster watches for the colour injected by the moon phase display.

Reference 03.2530.4047.78.C813

Skeleton decoration

The dial perpetuates the El Primero look based on intersecting circles, but these are laid out differently, with the moon phase at 6 o’clock, 30 chronograph minutes at 3 o’clock, continuous seconds at 9 o’clock, and the big date discs with cut-out numerals above at 1 o’clock. You can see parts of the silicon escapement under the continuous seconds. Touches of red and blue enliven the dial, but it’s the colourful moon phase disc that makes the watch stand out. It has two discs, the usual double moon disc with a realistic moon, and the daylight disc that provides a day/night display, rotating once every 24 hours.

Good legibility

Even though it’s a visually complex dial, the seconds scale at the edge of the dial and the suspended hour markers with SuperLuminova ensure good legibility, The two chronograph hands are red-tipped, and the chronograph seconds hand has a Zenith star-logo counterweight. The brand logo is direct on the sapphire glass.

Reference 03.2530.4047.78.M2530

Large case

This is a large watch at 45 mm diameter, 15.6 mm thickness. The case is in stainless steel, with a two-colour version with pink gold bezel, hands and hour markers. Water resistance is a commendable 10 atm. The watch has a steel bracelet or a leather strap with rubber lining.

Movement

The El Primero 4047B integrated self-winding column-wheel chronograph can be seen through the caseback, with its distinctive oscillating weight. It runs at 36,000 vibrations per hour, 5 Hertz, and so can time events with a precision of a tenth of a second. It has a silicon lever and escape-wheel, and a total of 332 components, 32 jewels. Power reserve is over 50 hours.

Prices and availability

The Zenith Chronomaster El Primero Grande Date Full Open starts at €10,600 for the steel version with leather strap, €12,200 for the steel and gold version. The watches will be available from September 2017. Read more on the Zenith website.

Reference 51.2530.4047.78.C810, two-tone version in steel and pink gold