Seiko & Citizen Watch Forum Message Archive

...That the water resistance quoted on a watch is "static" water resistance? I.E. a 200m Seiko can sit perfectly still under 200m of water and not bust a gasket.

However, as a diver is MOVING through the water, the DYNAMIC pressure against a watch may be many times more than the static pressure. Therefore, at 50m, a particularly violent arm movement might put more pressure against, say, the crystal of the watch, and a 200m watch could take it, while a 70m would spring a leak somewhere.