Summer has anticipated its arrival by more than 20 days. And I bet every watch enthusiast has pulled a diver's watch out of the drawer. It is certainly the smartest choice for not taking your timepiece off your wrist at sea. Although it is not the only one. In many cases, to be on the safe side, one can opt for a watch with a case that is water-resistant to 100 metres, without it meeting all the requirements to be called a diver.
These requirements are set out in ISO 6425, published by the International Organisation for Standardisation. The same one that defines the exact length of the metre, for instance.
According to the ISO 6425 standard, introduced in 1996, the minimum requirements for a diver's watch are: resistance to immersion in water to a depth of at least 100 metres and the presence of a time-presetting device. This device must be protected against unintentional rotation or incorrect handling. If it is a unidirectional rotating bezel, or one that can be locked in some other way, it must have a minute scale up to 60, with clear markings indicating 5 minutes.
There are many more specifications defined by the standard, and not only that: ISO 6425 imposes a series of tests for water tightness and general resistance to mechanical stress and magnetism, which must be performed by independent laboratories. ISO does not have a structure for performing the tests, but it does define in detail the methodology to be followed.
Already from the standards I have described, it is clear how the performance required of a diver far exceeds that needed for 'quiet' use of the watch at the beach. Next week, therefore, I will give you an example of my personal decalogue for choosing a holiday watch for those who do not intend to engage in diving.
Dody Giussani
