Jaeger-LeCoultre's Polaris collection welcomed two new members with technical upgrades that push them into the realm of professional-spec diver’s watches this month. The new arrivals – Polaris Mariner Memovox and Polaris Mariner Date and – are compliant to ISO 6425 specifications, are both depth-rated to 300 meters and feature a unidirectional inner-rotatable bezel with a 15-minute marker. More importantly, the Polaris Mariner Memovox is fitted with a sapphire crystal caseback allowing the user to see the hammer in action when the alarm does its thing. We got Lionel Favre, product design director at the Le Sentier-based brand to tell us more. Here are the excerpts:

WT: Can you tell us a bit about the challenges of integrating a striking mechanism in a watch with a sapphire crystal caseback and a water-resistance of 300 meters?

LF: First, because of the water resistance, the resonance in the case is reduced, so you need to create a mechanism that strikes with strength in order to be loud. Even more when the watch is worn on a swimsuit. Second, a diving watch is more exposed to several shocks as well as water pressure.

The striking mechanism of the alarm is now visible via the caseback

These were the two main challenges for our watchmakers when making this Polaris Mariner Memovox. They responded with a mechanism striking 77 times in 1 minute as well as other technical innovation such as the peripheral gong fixed to the case.

The two Polaris Mariner watches are the sportiest duo we have seen from Jaeger-LeCoultre in recent years after the Deep Sea or the Master Compressor models of the past. Is this part of the brand's move towards consolidating the Polaris as its sports watch range?

We have great ambitions for the Polaris collection, which today represents our sports segment and our desire to offer watches with a more contemporary style that combines watchmaking tradition and timeless design, two strong elements of our Maison’s DNA.

The original Polaris Memovox from 1968

The Polaris Mariner Memovox and the Polaris Mariner Date which are in the continuity of the spirit of the collection and of the first Polaris Memovox from 1968, which was designed for diving and allowed to warn the diver, thanks to the alarm, that he was coming back to the surface.

The design of a sports watch is often more assertive and more easily recognizable, which is perhaps one of the reasons for this growing success.

Do you think the demand for luxury steel sports watch is stronger than ever now?

Sports watches have always attracted interest for their practicality and durability. Today they are particularly appreciated for casual wear, easy to wear in all circumstances. The design of a sports watch is often more assertive and more easily recognizable, which is perhaps one of the reasons for this growing success.

How does the collector community react to the relaunch of the Polaris in 2018? Does feedback from the community feed in the product development?

The collection was very well received at its launch, collectors or historical fans of the Polaris have always had a soft spot for the Memovox model of 1968 in particular, they were happy that the new design did not distort the original one. We listen very carefully to the comments of our customers, collectors and non-collectors alike.

The Polaris Mariner Memovox

When we develop new watches, we are always looking for ways to improve on the points that have been brought to our attention. We also study the aesthetic comments, but here it is more difficult to satisfy everyone.