The draw of the U.S. Highway 90 bridge, mile 2.8, at Lake Catherine, shall open on signal; except that, from 5:30 a.m. to 7:30 a.m., Monday through Friday except Federal holidays, the draw need open only on the hour and on the half-hour for the passage of vessels. The draw shall open at any time for a vessel in distress.
33 C.F.R. §117.436