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.

 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.

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

 An artificial structure, like a small jetty, extending from the shore. Usually for the purpose of preventing beach erosion. Treated as a harborwork. Part of the coast line from which Submerged Lands Act grants and zones of maritime jurisdiction are measured.

 A place where ships may find shelter. A harbor may be natural or artificially constructed. In either case its waters are inland. The limits of its inland waters are determined, at least in part, by their use as a harbor rather than the mere application of delimitation principles to geography, as is the case with bays and rivers.

 Artificial structures erected to protect the coast or provide shelter. Treated as part of the coast line pursuant to Article 8 of the 1958 Convention and LOSC Article 11.