Switzerland is not really close to the sea nevertheless Switzerland played a key role within the Navy history and Time keeping.
The time measures history is coming from the first civilisations (Egypt, China). Time measures became a major concern, in particular to organize the social, religious and economic life of communities. Different periodic phenomena, such as shadow daily shift, seasons return, moon cycle was used as first baseline.
Step by step, Human being was inspired by physical phenomena for which he noticed periodic features. He created and set time measure systems more and more accurate and defined appropriate units. The balance wheel applied to mechanical watches, is the best example : these tools have been be defined and understood hour at anytime and anywhere.
The observatories of chronometry are located in countries for which horology and time measure raised high levels of art and excellence over several centuries. Following Switzerland, France, Germany and England built observatories by end of 19th century to certify the quality of their regional production.
Each piece proposed at final stage and full completed ready to be delivered, must be controlled during 16 consecutive days within 5 different positions under a temperature range from 8°C to 38°C. The values measured daily must be compliant with the ISO 3159 standard which allow insignificant daily rate deviations, within an average daily rate value from -4 to +6 sec. With all criteria covered, each chronometer receives its own individual numbered certificate.