Geographical Definition of Mississippi Sound

Boundaries for Mississippi Sound are determined by application of definitions, established surveying practices and observations of the physical processes of the area. U.S. Coast and Gcodetic charts 1266 (1972 edition), 1267 (1972 edition) and 1268 (1974 edition) were used in ascertaining the boundaries. These boundaries provide a formal geographical definition for Mississippi Sound. The geographical boundaries of Mississippi Sound are illdefined by natural features especially at the western end. This lack of generally recognized boundaries is a cause of confusion among individuals and agencies with an interest in this water body. Because of this vagueness, it is presently necessary to provide a chart or clear description of the area one refers to as “Mississippi Sound.” Of the several definitions of a sound (Gary et al. 1972), two seem appropriate for Mississippi Sound: ( 1 ) “An arm of the sea forming a channel between a mainland and an island”; (2) “A long, large, rather broad inlet of the ocean, generally extending parallel to the coast.” Mississippi Sound (Figure 1) is an elongated basin with its major axis parallel to the Gulf of Mexico from which it is partly separated by a series of barrier islands. U S . Coast and Geodetic charts 1266 (1972 edition), 1267 (1 972 edition), and 1268 (1 974 edition) were used in determining the boundaries of Mississippi Sound. The line segments shown are what the author proposes to be boundaries that are justifiable by definitions, accepted surveying practices and observations of the physical processes within the basin. The problem of defining the specific limits between two bodies of water is not always a simple one. The solution lies Manuscript received August 11,1978; accepted October 2, 1978. in finding the exact place where the water bodies merge, The “headland-to-headland’’ principle (Shalowitz 1964) has been deduced based on consideration of the physical config uration of the water bodies. This principle considers the boundary between a tributary water body and a larger water body to be a line joining the headlands of the tributary water body. The headland rule has been applied in various contexts to bays and rivers. Two rules (Shalowitz 1964) have been established in the case of determining boundaries where rivers flow directly into a water body. Cognizance has been taken internationally of the headland-to-headland principle at the 1930 Hague Conference for the Codification of International Law. The proviso contained in the final report of the Second SubCommittee of the conference states that “when a river flows directly into the sea, the waters of the river constitute inland waters up to a line following the general direction of the coast drawn across the mouth of the river, whatever its width.” The second rule provides that “if a river flows directly into the sea, the baseline shall be a straight line across the mouth of the river between points on the low-tide line of its banks.” This rule is a recommendation of the International Law Commission in its final report to the United Nations, as is Article 13 of the 1958 Convention on the Territorial Sea and the Contiguous Zone. The recommendation of the International Law Commission is the convention Figure 1. Mississippi Sound showing location of State and natural boundaries.