Introduced last year, the Montblanc Heritage Perpetual Calendar was the most affordable perpetual calendar – priced at US$12,800 in steel – from a major brand. For Watches&Wonders 2015 that takes place in Hong Kong next month, Montblanc has jazzed it up with a grey sapphire dial that shows off the gears and levers that keep the calendar perpetual.

The case is red gold, 39mm in diameter, with sapphire crystals front and back. It has clean lines, and a polished finished all round. Lightly tinted a smoky grey, the dial has facetted red gold-plated indices along with red-gold plated hands. All the of the perpetual calendar module is visible, including the snail cam for the date indicator at three o’clock.

At six o’clock the moon phase disc is shown in its entirety, but the lower half is engraved with a concentric guilloche to mark it out from the upper half that show the current age of the moon.

Able to keep track of the correct calendar till the year 2100, the perpetual calendar module is made by Dubois Depraz, a complications specialist that supplies the same module to several other brands in a similar price range. And the base movement for the watch is the robust but common ETA 2892.

That’s why last year’s solid dial version of this is the most affordable perpetual calendar from a mainstream brand, priced at US$12,800 in steel and US$21,600 in red gold. The price of the sapphire dial version is only slightly higher, at S$31,500 or €19,900 (equivalent to US$22,900).

The Zenith Christophe Colomb Hurricane Grand Voyage II is the second instalment in a series of watches dedicated to the Italian explorer. Like the first edition, the Christophe Colomb Hurricane Grand Voyage II is equipped with Zenith’s unique gyroscopic escapement as well as chain and fusee constant force mechanism. On its back Columbus and the indigenous peoples of the New World are depicted in hand-engraved relief.

On the back the bridges of the movement provide the canvas for the miniature. Each element is a piece of gold, engraved and painted by hand. The detail and depth is impressive, though the theme is a contentious one (bringing to mind another Zenith, the Latin American revolutionary-themed Hurricane Revolución).

Whereas the first edition of the Grand Voyage watch just portrayed Columbus and his ship, the Grand Voyage II illustrates the discovery of the Americas in 1492. On the right Columbus stands steadfast under the flag of Imperial Spain, while on the left the natives stand. The chief is wearing feathers and carrying a parrot, while his female companion is bearing a plate of fruit. In the background three ships can be seen on the horizon, the Niña, Pinta and Santa Maria.

The midnight blue dial on the front is actually the main plate of the movement, which has been engraved with stars and the Zenith logo in relief, and then lacquered around the reliefs. Each of the three sub-dials is a gold ring covered in white enamel.

Just below the sub-dial at 12 o’clock that shows the time is the chain and fusee. Essentially a cone linked by a chain to the barrel, it uses the principle of leverage to even out the power delivered by the mainspring. As the mainspring winds down, the chain unwinds from the cone, from top to bottom, compensating for the diminishing torque.

585 individual components make up the chain

The gyroscopic escapement at left, and the fusee with the chain coiled around it on the right

A consistent power delivery throughout its running time is one half of the story (though Zenith did just use that one half in another wristwatch). The other is the regulator, which is suspended in an extraordinarily complex system of gears – the gyroscopic carriage alone is 173 parts – that not only keeps the escapement ticking, but also keeps it level at all times.

Functioning like the gimbals in a marine chronometer, the gyroscopic escapement keeps the balance wheel parallel to the ground. In that position, gravity acts on the balance evenly all the time, which means there are no gravitational errors in timekeeping.

Like Zenith’s signature El Primero movement, the Hurricane movement runs at 36,000 beats per hour (bph), higher than the 28,800 bph of a typical movement. A higher frequency means greater inertia of the balance wheel, which promises more stable timekeeping since the balance is more likely to continue as it is, regardless of shocks. The watch has a case diameter of 45mm, large enough to accommodate the gyroscopic escapement as well as the chain and fusee, both of which are particularly large mechanisms. And the spherical motion of the escapement means that the sapphire crystal on the front and back have a protruding bubble.

The Christophe Colomb Hurricane Grand Voyage II is limited to just 10 pieces, with a price of US$353,000.