Section 117.1089 - Manitowoc River(a) The draws of the Eighth Street bridge, mile 0.29, and Tenth Street bridge, mile o.43, both at Manitowoc, shall open on signal except that: (1) From April 1 through October 31, Monday through Friday, the bridges need not open from 6:50 a.m. to 7 a.m., 7:50 a.m. to 8 a.m., 11:55 a.m. to 12:10 p.m., and 12:45 p.m. to 1 p.m., except federal holidays. From 10:30 p.m. to 4:30 a.m. the draws shall open on signal if at least a 6 hour advance notice is given.(2) From November 1 through March 31 the draws shall open on signal if at least a 12 hour advance notice is given.(3) The opening signals for these bridges are:(i) Eighth Street-one prolonged blast followed by one short blast.(ii) Tenth Street-two short blasts followed by one prolonged blast.(4) When signal is given by car ferry or other large vessel to pass either of the two bridges, the remaining bridge shall open promptly so that such vessels shall not be held between the two bridges.CGD09-01-001, 66 FR 13434 , Mar. 6, 2001, as amended by USCG-2015-0132, 80 FR 24816 , May 1, 2015