A grey area is an area lying within 200 miles from the coast of one state, but beyond a maritime boundary with another state. One state is excluded from exercising jurisdiction in this area because it lies beyond the maritime boundary, and the other state is excluded from exercising 200-mile-zone jurisdiction because the grey area on its side of the boundary lies beyond 200 miles from its coast. The possibility of creating a grey area stems from the fact that there is a discrepancy between entitlement to the EEZ and the principles applicable to its delimitation. Entitlement to this zone is solely based on distance from the coast, but its delimitation between states can be effected on the basis of principles other than distance from the coast. This results in a line which reaches the outer limit of the EEZ at a point which is non-equidistant from the coasts of the states concerned. If such a line is applied to limit the maritime zones of both states involved, a grey area is created. Apart from an EEZ delimitation, a grey area can also result from a territorial sea delimitation. A number of bilateral treaties have established a grey area. This raises the question whether such delimitations are only the result of practical considerations or a political compromise, or whether it is also possible to create a grey area in the legal determination of a boundary. This article seeks to answer this question looking at state practice and the case law.