33 CFR §117.625

1. (a)The draw of the Military Street Bridge, mile 0.33, shall open on signal; except that, from May 1 through October 31, from 8 a.m. to 11 p.m., seven days a week, the draw need open only on the hour and half-hour for recreational vessels, or at any time when there are more than five vessels waiting for an opening, and from November 1 through April 30 if at least 12-hours advance notice is given.
2. (b)The draw of the Seventh Street Bridge, mile 0.50, shall open on signal; except that, from May 1 through October 31, from 8 a.m. to 11 p.m., seven days a week, the draw need open only on the quarter-hour and three-quarter-hour for recreational vessels, or at any time when there are more than five vessels waiting for an opening, and from November 1 through April 30 if at least 12-hours advance notice is given.
3. (c)The draw of the Tenth Street Bridge, mile 0.94, shall open on signal; except that, from May 1 through October 31, from 8 a.m. to 11 p.m., seven days a week, the draw need open only on the hour and half-hour for recreational vessels, or at any time when there are more than five vessels waiting for an opening, and from 11 p.m. to 8 a.m. if at least 1-hour advance notice is provided, and from November 1 through April 30 if at least 12-hours notice is given.
4. (d)The draw of the Canadian National Railroad Bridge, mile 1.56, shall open on signal; except from November 1 through April 30 if at least 12-hours advance notice is given.