N.H. Rev. Stat. § 1:14

Subject to such lateral marine boundaries as have been, are herein or shall hereafter be legally established between this state and the state of Maine and the commonwealth of Massachusetts, the territorial limits and jurisdiction of this state shall extend to and over, and be exercisable with respect to, waters offshore the coast of this state as follows: I. Marginal Sea. The marginal sea to its outermost limits as said limits may from time to time be defined or recognized by the United States of America by international treaty or otherwise. The coastal baseline of this state from which the breadth of the marginal sea is measured shall be drawn in conformity with the treaties to which the United States is a party. Subject to future change as hereinabove set forth, the marginal sea is three nautical miles in breadth. II. The High Sea. Beyond the marginal sea, to the outer limits of the territorial sea of the United States of America and to whatever limits may be recognized by the usages and customs of international law or any treaty or otherwise according to law. This state claims title for a distance of two hundred nautical miles from the coastal baseline of the state, or to the base of the continental shelf, whichever distance is the greater. III. Submerged Land. All submerged land, including the subsurface thereof, lying under the aforementioned waters.