33 CFR 117.169: Mare Island Strait and the Napa River.

(a) The draw of the Mare Island Drawbridge, mile 2.8, at Vallejo shall open on signal between the hours of 9 a.m. and 7 p.m. daily, and upon two hours advance notice all other times. When the drawbridge operator is present, mariners may contact the drawbridge via marine radio or telephone at (707) 648-4313 for drawspan operation. When the drawbridge operator is not present, mariners may contact the City of Vallejo via the same telephone number to schedule drawspan operation.

(b) The draw of the Northwestern Pacific railroad bridge, mile 10.6 at Brazos, shall be maintained in the fully open position, except for the crossing of trains or for maintenance. When the draw is closed and visibility at the drawtender's station is less than one mile, up or down the channel, the drawtender shall sound two prolonged blasts every minute. When the draw is opened, the drawtender shall sound three short blasts.