When do I start my watch?

Under Article 102.16.3A:

• Be in position at the start with a clear view of the starting signal.
• Start your watch the instant you see the visual starting signal (the strobe or flash on the starting system).
• If you can't see the visual signal, start the watch when you hear the starting signal.

A loudspeaker start system with an electronic strobe visible to all manual timers is the preferred starting device (101.1.1).