The 1940s saw an intensification of Panerai’s collaboration with the Royal Italian Navy for the design and production of precision instruments to equip the underwater commandos. These included compasses and depth gauges, but also and most importantly watches, which were indispensable for synchronising all the operations to be carried out in the Mediterranean Sea, during which a difference of a few seconds could have a fundamental effect on the success of an operation. It was therefore necessary to equip the special forces of the Navy with a watch which had a very visible indication of the seconds, as well as of the hours and minutes. The solution was found through the adoption of a hand-wound Angelus® movement with eight days of power reserve and the small seconds counter positioned at 9 o’clock, which enabled the operations of the commandos to be synchronised perfectly. Since then, the small seconds indicator at nine o’clock has been an unmistakable element of many of Officine Panerai’s watches and in particular of the Luminor Marina.