Polaris Mariner Memovox is the latest in a long line of alarm diver's watches Image Credit: Supplied

This year Jaeger-LeCoultre’s Polaris collection welcomes two new members with technical upgrades that push them into the realm of professional-spec diver’s watches. The new arrivals – Polaris Mariner Memovox and Polaris Mariner Date – are compliant to ISO 6425 specifications, are both depth-rated to 300 metres 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 function is set off.

The Jaeger-LeCoultre Polaris Mariner Memovox is the latest in a long line of alarm diving watches from the Swiss brand spanning at least five decades. Unveiled today, the Mariner Memovox and the Mariner Date are two professional-spec diver’s watches depth-rated to 300 meters and a unidirectional inner-rotatable bezel. More importantly, for the first time users can actually see the mechanical alarm in action thanks to a sapphire crystal caseback.

From left: Memovox from 1950, Deep Sea Memovox (1959) and Polaris Memovox (1968) Image Credit: Supplied

Jaeger-LeCoultre introduced the Memovox in 1950 as its first wristwatch with an alarm. The period through 1950’s and 60’s is considered the Golden Age of recreational diving. Every important diver’s watch – from the Rolex Submariner to Blancpain’s Fifty Fathoms and Seiko’s Ref. 6217-8000/1 ‘62MAS’ – was released during this period. The alarm complication would eventually roll out to Jaeger-LeCoultre’s diving watches too with the launch of the Memovox Deep Sea in 1959. It made perfect sense – the watch had a visual timer (on the bezel) as well as a vibrating alarm to inform the user about time spent underwater.

In 1968, Jaeger-LeCoultre launched what would become its coolest diver’s watch yet – the Polaris Memovox. Its characteristic super compressor case had a multi-layer caseback that optimised the alarm’s sound transmission under water. The case was fitted with three crowns - the first crown for time setting, the second to rotate the inner bezel, and the third to set the alarm time. The outer case had 16 holes that amplified the alarm tone while the inner case sealed and protected the movement. Less than 2,000 examples of the Polaris hit the market, adding to its allure and desirability.

After a limited edition to mark the 40th anniversary in 2008, Jaeger-LeCoultre presented an entire collection inspired by the 1968 diver for its 50th anniversary in 2018. The flagship model was a limited edition Memovox powered by Caliber 956, the brand’s first automatic movement with alarm function.

The Polaris Mariner Memovox is a pro-spec diver's watch Image Credit: Anas Thacharpadikkal

The new Polaris Mariner Memovox has a stainless steel case that is 42 mm in diameter and 15.63 mm thick. It retains the classic design codes of the Polaris – the case has brushed surfaces with polished and beveled lugs and is topped by a glass-box crystal. The screw-down middle crown is used to move the bezel in one-minute increments around the dial. An orange security band on the crown stem serves to warn users if the crown is not screwed-in completely. The top crown is used to arm and set the alarm as well as the date while the lower crown is tasked with the adjustment of the hour and minutes hands.

The blue gradient dial comprising three concentric circles is finished in different textures - while the centre of the dial has a sunray-brushed finish, the middle ring has a grained texture. The outer band that holds the trapezoid-shaped indexes and Arabic numerals has an opaline finish. Legibility is excellent - the hands, numerals and indexes are coated with Super-Luminova, the minutes hand and the hour hands light up differently in the dark ensuring there is no confusion in reading time underwater. The running seconds hand is tipped in orange for daylight visibility, with a central luminescent section to avoid any possibility of confusion with the other hands.

The hours and minutes hand have different coloured lume Image Credit: Supplied

This far all Memovox models have been presented with closed casebacks. On the self-winding Calibre 956’s striking mechanism, sound is produced when the hammer hit the gongs fixed to the back of the case. To enable the use of a transparent sapphire caseback, the striking mechanism had to be redesigned with the gong now attached to the case side.

You can flip the watch over to see how the hammer goes when the “school-bell” sound of the alarm comes on. Through the open-worked rotor, you can see the traditional Swiss movement decorations like côtes de Genève (Geneva Stripes) on the movement plates.

The hammer is now visible on thanks to a sapphire crystal caseback Image Credit: Anas Thacharpadikkal

A simpler Polaris Mariner Date was also launched as part of this new performance watch sub-collection of the Polaris. It runs Calibre 899, a self-winding movement that Jaeger-LeCoultre uses in the Master Control line. Unlike the earlier versions that had a power reserve of 43 hours, the updated Calibre 899 used in the Polaris Mariner Date is good for 70 hours.

Both watches are presented with a stainless steel bracelet with a folding buckle. The three-link bracelet has brushed central and polished outer links and is extremely comfortable on the wrist. While the Polaris Mariner Memovox is priced at €14,500 (without VAT), the Mariner Date will retail for €9,100 (without VAT).