The Polaris Mariner line originates in two historic Jaeger-LeCoultre watches: the Memovox, introduced in 1959 and the first automatic dive watch with an alarm function, and the Memovox Polaris, launched in 1968 with a rotating inner bezel and a triple caseback for improved sound transmission. This new interpretation is powered by the automatic Calibre 956 which has been comprehensively revised for this latest generation alarm watch. The hammer for the alarm can now be seen in action through the transparent back. This meant a complete redesign of the striking mechanism, with the gong now attached to the side of the case. The triple-crown configuration is a signature of the very first Memovox dive watches: the top crown controls the alarm, the middle crown operates the inner dive bezel and the bottom crown sets the time. Water-resistant to 300 metres.