(a) The draws of the Northwestern Pacific railroad bridges, mile 0.8 at Blackpoint and mile 12.4 at Haystack Landing, shall be maintained in the fully open position, except for the crossing of trains or for maintenance. When the draw is closed and visibility from the drawtender's station is less than one mile up or down the channel, the drawtender shall sound two long blasts every minute. When the draw is reopened, the drawtender shall sound three short blasts.
(b) The draw of the Petaluma highway bridge at ``D'' Street, mile 13.7 at Petaluma, shall open on signal if at least four hours notice is given for openings from 6 a.m. to 6 p.m., and if at least 24 hours notice is given for openings from 6 p.m. to 6 a.m. [CGD 82-025, 49 FR 17452, Apr. 24, 1984, as amended by CGD 11-88-10, 53 FR 51099, Dec. 20, 1988; USCG-2001-10881, 71 FR 70309, Dec. 4, 2006]