I plug all of the Vhf and Uhf P25 pertaining to the New England area.
171.2375/ Cape Cod Canal
345.0000 (AM)
412.9750
162.3250
164.9000 (Sector Boston)
150.7000 (not sure if still in use.) USCG Net.
If you are on the Cape close to the base you can also plug in the maintenance channel 166.2250. I get this frequency from New Bedford quite a bit. And if your interested in the Air operations. 164.550 is used a little bit. And the coast guard Otis Tower is on 128.425 if you are interested in Coast Guard Air operations. 173.4375 NAC:200 is used for the Canal. Think by the Army Corps of engineers. The New Bedford Hurricane Barrier also uses this frequency for the barrier operators.