A great number of people expect that a water resistant timepiece is good for swimming or diving. Actually, there are watches of various resistance to water: while some watches can withstand long-time contact with water, other timepiece break down after several minutes after being in water. Vast majority water-resistant wristwatches can withstand a short-time contact with water, but such watches should not be used for swimming and definitely they should not be used for diving. It is very important to read all markings on the timepiece thoroughly and to know what these markings mean. Never swim or dive with a timepiece that features the marking "water resistant" 3 ATM (30 m)". There are watches with higher water resistance - to 50m, you should remove such a wristwatch if you want to dive, but such a watch will withstand swimming. The nicest timepieces are those with water resistance to 10ATM (100 m), these are appropriate for diving. Also lots of people suppose that imitation wristwatches are highly water-resistant, but this is wrong. Only authentic watches, can be used for diving, so a Rolex Oyster facsimile timepiece is not the greatest alternative for a diver. You must understand that an imitation Rolex watch imitates an original Rolex wristwatch ideally, but it is not so perfect. Be aware that imitation watches damaged by water are not accepted for refund, the same refers to authentic wristwatches that are not marked as water-resistant to 10 ATM or more.