Not stationary. Baselines from which maritime boundaries are measured ambulate with accretion and erosion causing ambulation of the boundaries themselves.

 Offshore structures or features that do not meet the LOS Convention's definition of "island" in that they were not "naturally formed." Mineral production platforms and spoil banks are examples. Artificial islands are not part of the baseline from which maritime zones are measured.

 An indentation of water into land that meets the requirements of Article 7 of the 1958 Convention on the Territorial Sea and the Contiguous Zone and Article 10 of the LOSC. An inland water body.

 A man-made structure extending seaward from the natural coastline which has an apparently continuous low-water line. Often constructed to affect the movement of water. A harborwork. Part of the coast line from which maritime zones are measured. Often contrasted with piers.

 The line dividing inland waters and the territorial sea at the mouth of a river, bay, or harbor.

 Lines constructed by the United States Coast Guard to separate areas of the sea where the Inland Rules of the Road apply from those where the International Rules are in effect. Found by the Supreme Court to have no bearing on the location of the coast line or inland waters as those terms are used in the LOSC and the 1958 Convention.

 The term used in the Submerged Lands Act to describe the low-water line and closing lines across the mouths of inland water bodies. The same as "baseline" in the LOSC and the 1958 Convention.

 Man-made structures erected along the coast, such as jetties and groins. Harborworks. Treated as part of the coast line for purposes of maritime zone delimitation.

 The water/land interface. The shoreline. A more general term than "coast line."

 A pair of adjacent bays that share a central headland. If, when considered together, the two indentations meet the requirements of Article 7 of the 1958 Convention and LOSC Article 10, they may be combined to form a single juridical bay with a closing line joining their non-common headlands.