The drawspan for the State Road 789 Drawbridge, mile 0.05, at Sarasota, need only open on the hour, twenty minutes past the hour, and forty minutes past the hour from 7 a.m. to 6 p.m. From 6 p.m. to 7 a.m., the drawspan must open on signal if at least 3 hours notice is given to the drawtender. Public vessels of the United States and tugs with tows must be passed at anytime.