Your Charles David® chronograph watch has special functions that you may not understand. In addition to the impressive design, your enjoyment while wearing it will be greatly enhanced by understanding the following explained functions.

Stop Watch:
The Stop Watch (Chronograph) is useful for timing events that require the recording of start and finish times. By pressing the lower pusher button, below the center crown, the chronograph second hand will sweep to the top of the dial and stop. The chronograph minute hand will also reset. When the event begins, press the upper pusher button, above the center crown. The chronograph second hand will begin to sweep and the chronograph minute hand will also begin movement. Immediately upon termination of the event, pressing the upper pusher button again will stop the timing function. Read the chronograph minute hand and chronograph second hand to determine the elapsed time.

Tachymeter:
The “Tachymeter” is a numeric feature  that  can be  used  to  measure  the  speed  of  a moving  vehicle.  The Tachymeter scale is inscribed around the circumference of the watch dial. A standard Tachymeter will only determine speeds greater than 60 miles/kilometers per hour. Slower speeds can be measured by reducing the unit of measurement. The scale is generally only accurate for elapsed times over approximately 7 seconds. To effectively measure speed, a specific distance must be traveled. 1 mile/kilometer is the common unit of measure used. To use the Tachymeter, establish specific start and finish points. Mile/kilometer markers are useful references for  determining speed. Reset the chronograph second hand by pressing the lower pusher button, below the center crown, the chronograph second hand will reset to the top of the dial. Press the upper pusher button, above the center crown, at the starting reference point. The chronograph second hand will begin to sweep toward “500” on the Tachymeter scale. When a specific distance has been traveled, such as one   mile/kilometer, press the upper pusher button again and the chronograph second hand will stop. The speed for distance traveled will be indicated on the Tachymeter scale. Remember that a speed of 60 miles/kilometers per hour must be achieved to be effective. Obviously, rate of speed for most anything can be determined using this criteria.

ATM Rating:
The Magma Watch is rated at 10 ATM or atmospheres. 1 ATM = 33 feet below the surface of the ocean. The structural integrity of the watch will be maintained to a depth of 330 feet. However, as with any watch, in time, seal deterioration is inevitable. Servicing the seals and gaskets every 3 to 5 years by a qualified jeweler is recommended.