In the 1990’s, the International Organization for Standardization ( an international standard-setting body composed of representatives from various national standards organizations) issued standard 2281, this prohibited watch companies to use the term waterproof this is why no watch is technically “waterproof” later the ISO described all the things needed for a watch to qualify as a “dive watch”. They required every watch to be 25% more water-resistant than being claimed on the dial. Plus, underwater visibility, being resistant to temperature changes and tracking elapsed time were some more of the requirements. Watches that met these requirements were marked with the word “Diver” to separate them from watches not suited for diving. This level of standard is still being used today, by manufacturers.
The first record of a truly water-resistant watch came from London, England, in 1851. It was produced by a Swiss manufacturer, named Petit and Co., who claimed,”The object of this invention was to secure the protection of time-keeping and other instruments from water, sea dampness, and rust”. He created a display suspended in a glass globe, filled with water, and surrounded with gold and silver fish, a very unique and simple way to show what their watches could stand up to.
The next big break in the history of watch water resistance was in 1871 when a man by the name of Aaron Lufkin Dennison registered the first patent for a water-resistant watch. This patent described a watch with a case that was air and water tight by screwing on both the back and the bezel. In order to make his watches water-resistant Dennison replaced the normal bezel with an upgraded version. An external screw thread was screwed onto the front of the watch from the inside. The back of the case then had internal threads that screwed onto a thread formed on the middle of the case. This invention is still used on modern screw down case backs, to this day.
On April 22, 1879, a patent was granted to Ezra C. Fitch for a watch with a case that did not open. There was a removable screw down cap that sealed up the crown of the watch. In 1881, Ezra Fitch came up with a new way to make the crown of the watch water tight; instead of a cap, the watch crown itself had internal threading that would screw to the pendant. This was the start of the familiar ‘screw down crown’ used in modern dive watches today.
In 1883, Ezra Fitch became President of the American Watch Company of Waltham. Waltham watches, using his patent to waterproof his watches with a screw down crown, are made commercially available for the first time. However the public perception was in agreement that it seems a water proof watch is too complicated and expensive to produce for the public and the design does not have success.
On May 20, 1919, Frederick Gruen, patented an idea that allowed watches water tight by placing the entire watch inside a larger secondary watch case. He then attached a screw on bezel and the case had no gaps making it completely air tight. Inside the case was a smaller watch inside of its own case. Even though the secondary case idea created a great way to get ample water resistance, it created some problems as well. The crown of the watch was not accessible from the outside so the outer case was unscrewed daily to wind the watch which put wear on the treading on the outer case.