33 CFR §117.305

1. (a)General. Public vessels of the United States, tugs, tugs with tows, and vessels in a situation where a delay would endanger life or property shall, upon proper signal, be passed through the draw of each bridge listed in this section at any time.
2. (b)The draws of the S.W. First Street Bridge, mile 0.9, up to and including the N.W. 27th Avenue Bridge, mile 3.7 at Miami, shall open on signal; except that, from 7:35 a.m. to 8:59 a.m. and 4:45 p.m. to 5:59 p.m., Monday through Friday, except Federal holidays, the draws need not open for the passage of vessels.
3. (c)The draws of the Miami Avenue Bridge, mile 0.3, and the S.W. Second Avenue Bridge, mile 0.5, at Miami, shall open on signal; except that, from 7:35 a.m. to 8:59 a.m., 12:05 p.m. to 12:59 p.m. and 4:35 p.m. to 5:59 p.m., Monday through Friday, except Federal holidays, the draws need not open for the passage of vessels.
4. (d)The draw of the Brickell Avenue Bridge, mile 0.1, at Miami, shall open on signal; except that, from 7 a.m. to 7 p.m., Monday through Friday except Federal holidays, the draw need open only on the hour and half-hour. From 7:35 a.m. to 8:59 a.m., 12:05 p.m. to 12:59 p.m. and 4:35 p.m. to 5:59 p.m., Monday through Friday except Federal holidays, the draw need not open for the passage of vessels.