33 CFR § 117.603 - Manchester Harbor.
The Massachusetts Bay Transportation Authority Bridge at mile 1.0 in Manchester, shall operate as follows:
(a) The draw shall open on signal -
(1) From Memorial Day through September 30 from 7 a.m. to 11 p.m.;
(2) From April 1 to Memorial Day and from October 1 to November 1 from 9 a.m. to 1 p.m. and 2 p.m. to 6 p.m.
(b) At all other times, the draw shall open on signal with at least four hours notice.
(c) The owner of this bridge shall provide and keep in good legible condition, clearance gauges for each draw with figures not less than twelve (12) inches high designed, installed and maintained in accordance with the provisions of section 118.160 of this chapter.