With summer holidays on many people’s minds a question I’m often asked by those about to set off to the sun is ‘Can I wear my watch in the pool, or in the sea?’

Well, the answer is ‘yes’…or it might be ‘no’…. depending on whether or not your watch is water resistant.

Watches which are water resistant are often marked on the back of the watch case with the level of water resistance, for example ‘30m’, ‘50m’ or ‘100m’, but what does this actually mean?

Lot 409 – Tudor - A steel ‘Prince Date’ chronograph wristwatch – manufacturer’s water resistance rating 100 metres. Estimate - £2000 - £3000. Available at the Cheffins Jewellery, Silver & Watches Sale on 4th August.

Many people think that if their watch is marked ‘30m’ it means that they can wear it in water and swim down to a depth of 30 metres, but surprisingly they would be mistaken! It simply means that the watch is able to withstand the equivalent water pressure that is found at depth of 30 metres. If you jump in a swimming pool, the pressure exerted on your watch at the point of entry into the water is much more than the pressure at 30 metres depth, so there is a very good chance you will end up with water in your watch and an expensive repair bill.

As a rule of thumb, I would recommend the following:

30m resistant – should survive hand washing, splashes of water or being caught in the rain.

50m resistant – should withstand swimming and showering.

100m resistant – should survive swimming and snorkelling.

200m+ resistant – suitable for diving.

If you are planning to take your watch on holiday and swim with it on, I would recommend a trip to your friendly watchmaker before you go to have the watch seals checked for water resistance. The seals between the case front and back, around the glass and under the crown ensure your watch stays dry while you’re having fun in the water, but they can deteriorate over time and will need replacing if you don’t want them to fail and leave you with a soggy lump of rusty metal where your watch used to be.

Lot 393 – Omega - A steel ‘Planet Ocean’ wristwatch – manufacturer’s water resistance rating 600 metres. Estimate - £2000 - £4000. Available at the Cheffins Jewellery, Silver & Watches Sale on 4th August.

Of course, when buying water resistant watches at auction I would strongly recommend having the seals checked before immersing the watch in water as a matter of course, as you will have no way of knowing their condition or even if they are in place at all.

When in the water with your watch, do not attempt to change the time, wind it up or use chronograph buttons. The buttons will be sealed to the case and disturbing them while wet may allow ingress of water. Always make sure your watch is dry before making any adjustments.

Lot 408 – Rolex - A steel and gold ‘Oyster Perpetual’ wristwatch – manufacturer’s water resistance rating 100 metres. Estimate - £1000 - £2000. Available at the Cheffins Jewellery, Silver & Watches Sale on 4th August.

After swimming in your watch – especially in the sea – run it under clean fresh water and dry it off. The salt in sea water is surprisingly corrosive and even the chemicals in swimming pools aren’t great for the watch case, seals and bracelet, so always make sure it’s flushed with fresh water before you head for the sun lounger!

And lastly, I was once asked by a client whether his sharkskin watch strap was waterproof! Well…what would you have replied?

Happy holidays!

To view the watches in the sale, please click here.