What exactly does Water Resistant mean?

A water resistance mark is commonly stamped on the back of watches to indicate how well the watch is sealed against water entering it. But it can sometimes be confusing to what water resistance actually means when it comes to watches, for example if a watch states that it is water resistant up to 100m, does that mean you can dive to 100m in depth? Unfortunately, the answer is no! What 100m resistance actually refers to is the static pressure experienced at a 100m depth, when a watch moves in the water the pressure naturally fluctuates, so a watch with a 100m water resistance is perfect for shallow diving or swimming, but not for deep sea diving.

 At W.E Clark and Son, we offer a full water pressure testing service with each watch tested to the manufacturer's recommended levels and also we can also boost pressures for those individuals who desire a watch that can stand up to more extreme leisure pursuits.

Once the watch has been tested and the seals checked, we use our state of the art Sigma Pressure Booster to amplify the compressor pressure up to 30 bar, which is the highest range for water resistance and within minutes you will be able to use your watch on your next scuba diving trip.

 The table below shows Water Resistance Classification:

Water Resistant 3atm or 30m

Suitable for everyday use. Splash/rain resistant.Not suitable for showering, bathing, swimming, snorkelling, water related work and fishing.

Not suitable for diving.

Water Resistant 5atm or 50m

Suitable for swimming, white water rafting, non-snorkeling water related work, and fishing.

Not suitable for diving.

Water Resistant 10atm or 100m

Suitable for recreational surfing, swimming, snorkeling, sailing and water sports.

Not suitable for diving.

Water Resistant 20atm or 200m

Suitable for professional marine activity, serious surface water sports and skin diving.

Suitable for skin diving.

Diver's 100 m

Scuba diving

Diver's 100m and 150m watches are generally old(er) watches.

Diver's 200 m or 300 m

Suitable for scuba diving at depths

Typical ratings for contemporary diver's watches.

Diver's 300+m for mixed-gas diving

Suitable for saturation diving


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 All watch repairs carry a 12-month guarantee