The water resistance values in metres quoted by watch manufacturers usually relate to the air pressure used in the water resistance test (ISO2281). They do not reflect actual dive depth! As a general rule then, the following is an general guide to the WR performance that you should expect from a watch. Water Resistant: Suitable for conditions of minor splashing, exposure to rain etc. 50 metres (5 BAR): Suitable for showering and swimming 100 metres (10 BAR): Suitable for snorkelling and pool side diving. 200 metres (20BAR): Suitable for high diving and scuba diving to normal amateur depths i.e. 35 - 40 metres (Source: Casio 2007)