Start sequence
idle
—:—
Warning−3:00
Prep−2:00
One-minute−1:00
Start0:00
Event signals (fire now)
Sound
Flags remain the official signal (RRS 26); this horn is a supplement.
📱 iPhone: turn the side Ring/Silent switch to Ring and raise
the volume — iOS mutes web audio when the phone is on silent. Tap Test tone to check.