Massachusetts is one of the few states in the United States where property owners who own property fronting on the Atlantic Ocean own to low water. This rule is from the Colonial Ordinances of 1641-1647 which states:
“It is declared that in all creeks, coves and other places, about an upon salt water where the Sea ebs and flows, the Proprietor of the land adjoining shall have properties to the low water mark where the Sea doth not ebb above a hundred rods, and not more wheresoever it ebs farther.”
This has been interpreted to mean that the upland owner owns to low water but no more than 100 rods (1650′) from high water. Exceptions to the rule are for “fishing, fowling and navigation”.
This rule does not apply in Rhode Island where the high water mark controls.
If you are interested in further reading you may want to consider reading Paul’s book Boundary Surveying in the Metes and Bounds States.