Most dive watches have a metres/feet depth rating printed on the dial, usually between the 6 and centre. A simple three or four digit figure indicating the threshold beyond which the watch is likely to fail due to water ingress, a shattered crystal or even complete implosion. Of course this is only a theoretical guide based on simulated conditions using pressure testing equipment in a lab. Very few owners of dive watches ever descend close to the “100M”, “200M” or “300M” depths on their respective dials and very seldom are watches actually tested at those depths. In 1964, when Ollech & Wajs successfully pressure tested a watch to the equivalent of -1000M (3300ft), more than three times the rating of the best dive watch available at the time, it was a difficult depth to comprehend. To this day no diver has ever experienced such depths. (Click to continue reading)