33 CFR § 117.624 - Black River (South Haven).
The draw of the Dyckman Avenue bridge, mile 1.9 at South Haven, shall open as follows:
(a) From May 1 through October 14 -
(1) From 7 a.m. to 11 p.m., seven days a week the draw need open only on the hour and half-hour; however, Mondays through Fridays the draw need not open at 12 noon and 1 p.m. Commercial vessels shall be passed through the draw of this bridge as soon as possible even though this regulated period is in effect.
(2) From 11 p.m. to 7 a.m., no bridgetender is required to be in continuous attendance at the bridge and the draw shall open on signal for commercial vessels and pleasure craft if at least a three hour advance notice is given.
(b) From October 15 through April 30, the draw shall open on signal for the passage of commercial vessels and pleasure craft if at least a twelve hour advance notice is given.