Marine belt
Defined in 1 dictionary — Black's (1910)
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
That portion of the main or open sea, adjacent to the shores of a given country, over which the jurisdiction of its municipal laws and local authorities extends; defined by international law as extending out three miles from the shore. See The Alexander (D. Ct) 60 Fed. 918.
Defined under Marine in Black's Law Dictionary.