N.Y. GBS Law § 262

§ 262. Center of river defined. The center of such river is hereby\ndefined to be a line halfway between low-water mark on the east bank and\nlow-water mark on the west bank of such river. Where an island\nintervenes, having an icehouse or icehouses thereon, the center of the\nriver, for the purpose of this article, is hereby defined to be a line\nin each channel into which said river is thereby divided, halfway\nbetween low-water mark along the shore of such island bordering upon\nsuch channel and the banks of such river opposite such island. Where\nthere are, or shall be, dykes erected along both banks of said river, or\nalong either shore of such island and also along the bank of said river,\nopposite thereto, the center of said river is hereby defined to be a\nline halfway between said dykes. Where there is, or shall be erected, a\ndyke along one shore of such island, or along one bank of said river\nonly, the center of said river is hereby defined to be a line halfway\nbetween said dyke and low-water mark along the opposite bank of said\nriver, or along the opposite shore of such island, where an island\nintervenes. Nothing in this article shall be construed to deprive the\npublic from the right to travel or drive over such ice for any or all\nlegitimate purposes whatever.\n