Waterproof watches.

Admin if this is in the wrong place please delete and merge but it's not a peeve as such.

Unless you have a need to see the time for whatever reason whilst submerged, why is for example "waterproof to 50 metres" even a selling point?
A friend showed me his nice new watch and seemed chuffed it had this level of waterproofing. Big deal. Who wears a watch whilst swimming or in the shower? And if you do, why?