Quoting Regatta-yachttimers.com: “Until 1974 the Aquastar brand watches were looked at as stricktly professional instruments, and were only available through professional diving equipment outlets and were never offered on a large scale to retail distributors. But that year Frédéric Robert retired and in 1975 Aquastar was acquired by the Eren Group, also established in Geneva. They made the Aquastar watches available to the general public through retail outlets.
The in part one described first Aquastar Regate from the 1960’s with the Felsa 4000N movement was limited with a 5 minute regatta countdown. And as the regulations changed for regatta’s, a new movement was developed by Aquastar, now with a 10 minute countdown. This time with the help of Lemania’s star designer Albert Piquet (his name is mentioned as inventor on the patent), and soon the new Lemania caliber 1345 was born!
With this new patent (CH563037, US3910362) Aquastar is at the origin of all regatta watch developments which have been made subsequently on this coloured disc model used as regatta countdown with minute indicator. The new Lemania regatta caliber 1345 is derived from the 1341 movement. After the introduction of the new Aquastar Regate the Lemania 1345 movement comes available for other brands as well.”
If you are wondering how the countdown function works, here’s a quick guide as explained by regatta-yachttimers.com:
The Lemania regatta caliber 1345 is like the Felsa caliber 4000N in the first Aquastar Regate a modified chronograph with fly-back function. It has the crown to set the time at 3 o’clock, and one pusher at 2 o’clock for start/reset of the countdown. Under the dial lays the indicator disk coloured silver, red and blue (or black, red and blue in case of a black dial). There are five round holes cut out of the dial, between 10 and 2 o’clock.
With the chrono activated the five dots colour blue and the sweep second hand returns to 60. By releasing the pusher the countdown starts and the sweep hand is set in motion counting backwards from 60 to zero. The indicator disk runs continuously clockwise. After one minute the first dot colours red, and after five minutes all 5 dots colour red. Again one minute later, so after 6 minutes, the first dot colours silver. And after 10 minutes all dots colour silver. The indicator disk stops revolving, but the second hand moves on.