33 CFR §117.1029

The draw of the Chambers Bay railroad lift bridge, mile 0.01, at Chambers Bay, shall open on signal except between 10 p.m. to 6 a.m. The draw shall open on signal from 10 p.m. to 6 a.m. when at least four hours of notice has been given via the phone number displayed at the bridge, and as soon as possible, no later than 1 hour after notification, for vessels engaged in emergency response.