What is Arm Of The Sea?

Legal Definition
Lord Coke defines an arm of the sea to be where the sea or tide flows or reflows. Constable's Case, 5 Co. 107. This term includes bays, roads, creeks, coves, ports, and rivers where the water flows and reflows, whether it be salt or fresh. Ang. Tide Wat. 61. Vide Creek; Haven; Navigable; Port; Reliction; River; Road.
-- Bouviers Law Dictionary
Legal Definition
A portion of the sea projecting inland, in which the tide ebbs and flows. 5 Coke, 107. An arm of the sea is considered as extending as far into the interior of a country as the water of fresh rivers is propelled backwards by the ingress of the tide. Ang. TideWaters, 73; Hubbard v. Hubbard, 8 N. Y. 196; Adams v. Pease, 2 Co.nn. 484; U. S. v. Grush, 5 Mason, 290, Fed. Cas. No. 15,268; Ex parte Byers (D. C.) 32 Fed. 404.
-- Black's Law Dictionary
Legal Definition
A bay or river where the tide of the sea ebbs and flows.
-- Ballentine's Law Dictionary