What is the method to find North using a watch?

To determine North using a watch, pointing the hour hand at the sun and measuring the angle to the 12 o'clock position is an effective method. The basic principle behind this technique is that a standard analog watch functions as a crude sundial. When you align the hour hand with the sun, you can establish a reference point for determining direction.

In the Northern Hemisphere, the point that bisects the angle between the hour hand and the 12 o'clock position pointing to North is approximately to the south. Thus, by measuring the angle to the 12 o'clock position, you can effectively find North.

This method requires that you know whether it's standard time or daylight saving time since the hour hand is adjusted accordingly. It is important to use the correct time to ensure the accuracy of your direction finding.

The other options do not apply correctly: aligning the watch with magnetic north would not aid in finding true north through solar alignment; reading magnetic coordinates from the watch face is not a function of standard watches; and holding the watch vertically to see the shadow doesn't provide any directional information for determining North effectively.