From the Mass General Laws:
Coastal waters'', all waters of the commonwealth within the rise and fall of the tide and the marine limits of the jurisdiction of the commonwealth, but not waters within or above any fishway or dam nor waters above any jurisdictional boundary legally established pursuant to section five of chapter one hundred and thirty of the General Laws in rivers and streams flowing into the sea"
All other water is defined as "Inland Water" and requires a fishing license. As always it would be best to check with local authorities for the situation where you intend to fish.
Pete
