A battery should last at least 30 months, depending on the type of watch, its size, and the energy required to power its various functions. A chronograph, for example, requires more energy than a watch that only displays hours and minutes. When the battery no longer works it should be removed or exchanged by a qualified service center.
Shocks: Avoid exposing the watch to shocks. If you have an accident with the watch, take it to your watchmaker to check its functions.
Cleaning: Do not forget to rinse your watch in fresh water after driving to prolong its life. Be sure to rinse your watch regularly with fresh water and soap especially after it has been in salt water. This helps to preserve its look and condition. Screw-in crown: Make sure water does not get into the mechanism.
Chemical Products: You may come across chemical products like perfumes, detergents or solvents daily. They may damage the bracelet, case or gaskets. Rinse immediately with fresh water.
Temperatures: Avoid extreme temperature changes, as well as extremely high temperatures (above 60 C) and extremely low temperatures (below 0 C) since these can cause condensation which may affect the functions of your watch.
A Tachymeter helps you estimate the speed you are going.
It uses the basic formula that speed = Distance/time
It tells average speed over a measured distance. Usually, it's a scale on the bezel that starts at 60 and goes to 400 or 500. Some older watches have spiral scales that start at 30. One way to use it is to push the button at 2:00 when you pass a mile marker on the highway. Push it again when you pass the next mile marker. The first push starts the stopwatch, and the next push stops it. If there is no stopwatch function, then just use the second hand. The watch's second hand on the stopwatch tells how long it took to travel that mile. The tachymeter scale tells your average speed in miles per hour for traveling that mile. You can do the same thing in Europe with kilometer markers. The reason the scale usually begins at 60 is that there are 60 seconds in a minute. If you travel at 60 miles an hour, that's a mile per minute, so it takes 60 seconds to travel a mile.
It's not as complicated as it seems. If a subdial has a 60 at the top, it's probably a continuously running second's hand (if the watch is working, this hand will be moving). But a few subdials with 60 at the top are actually 60-minute counters.
If the subdial has a 30 at the top, it's most likely a 30-minute counter. If it has a 12 at the top, it's probably a 12-hour counter (although if the watch is a dual-time-zone model, it's probably a second-time-zone indicator). If it has a 10 at the top, it probably measures 1/10th of a second.
Date subdials have a 31 at the top for the maximum number of days in a month. Moon phase subdials are obvious - they have a picture of a moon showing through the aperture - as are month and day-of-the-week subdials, which are labeled either Jan. through Dec. or Sun. through Sat.
A method of applying corrosion-resistant metal coatings. Ion plating is one of the most advanced surface finishing processes available. In traditional processes, the coating on the surface of the case or band can be rubbed off easily. Ion plating makes the plating more durable, more wear resistant, and also has a higher brightness. Ion plating involves adding of a titanium nitride layer.
| ATM | METERS | FEET | USAGE |
| 3 | 30 | 100 | Suitable for everyday use. Splash/rain resistant. NOT suitable for showering, bathing, swimming, snorkeling, water related activities. |
| 5 | 50 | 165 | Suitable for swimming, white water rafting, non-snorkeling water related activities. |
| 10 | 100 | 330 | Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. |
| 15 | 150 | 500 | Suitable for recreational surfing, swimming, snorkeling, sailing and water sports. |
| 20 | 200 | 660 | Suitable for professional marine activity and serious surface water sports. |
| 30 | 300 | 990 | Suitable for professional diving. |