33 CFR § 167.77 - In the approach to Boston, MA: Traffic separation scheme.

(a) A separation zone 1 mile wide is established and is centered upon the following geographic positions:

Latitude	Longitude
42°20.73′ N	70°39.06′ W.
42°18.28′ N	70°01.14′ W.
40°49.25′ N	69°00.81′ W.

(b) A traffic lane for northbound traffic is established between the separation zone and a line connecting the following geographical positions:

Latitude	Longitude
40°50.47′ N	68°58.67′ W.
42°20.17′ N	69°59.40′ W.
42°22.71′ N	70°38.62′ W.

(c) A traffic lane for southbound traffic is established between the separation zone and a line connecting the following geographical positions:

Latitude	Longitude
42°18.82′ N	70°40.49′ W.
42°16.39′ N	70°02.88′ W.
40°48.03′ N	69°02.95′ W.

[USCG–2010–0718, 75 FR 77534, Dec. 13, 2010]