M.O. Triukhan, V.M. Triukhan

Research Institute of Geodesy and Cartography, Kyiv, Ukraine


Cartographic and geodetic support or technical aspects of determination of maritime space play an important function in the maritime delimitation.

International maritime law gradually was adjusted and codified, especially due to Geneva Conventions (1958) and their successor, the United Nations Convention on the Law of the Sea (1982).

In practice, it is hard to distinguish purely technical (geodesy and cartography) and legal questions. Boundaries of States and their jurisdictional zones usually are indicated as a list of coordinates in Treaties. A cartographic supplement added to treaties has quite a small scale, and its character is rather illustrative. On the other hand, it is necessary to make numerous actions, including those on the base of maps, in order to receive the mentioned list.

The particularity of maps used is that all the maps are untrue, i.e. as two-dimensional representation of the complex three-dimensional (even four-dimensional, if time dimension is considered) world we live in, they do not necessarily provide with sufficient information.

Charts are produced in Mercator projection and have substantial distortions. They have a variable scale, that is why the measurements of line lengths and areas need adjustments (at the same time as the length of 1′ of latitude on the Earth surface constitutes 1852 m and equals to 1 nautical mile, 1′ of longitude on the 45 parallel of the Earth surface will be only 1320 m, though at the equator they are equal to each another other).

The lines, joining the points on these charts, appear as straight lines or loxodromes. On the terrain they will appear as arcs. Furthermore, charts usually depict a generalized coastline, especially at non-navigable sections.

Topographic maps are multi-purpose, and it is expedient to use them on all stages of delimitation. This will allow avoiding blunders during execution of necessary cartometric works, and calculations of areas for different versions of delineations.

The role of technical experts cartographers and geodesists in the process of informational support of the maritime delimitation is vitally essential. It must not only supporting of diplomatic negotiation process from cartographic and geodetic point of view (determination of coordinates, measurements, constructions, calculations of areas, illustration of all required operations), but also to secure a making decision process versus numerous errors, that may take place with such delicate issue as a maritime delimitation.