Strait of Gibraltar These "internal waves" continue to flow eastward and to refract around coastal features. They can sometimes be traced for as much as , and sometimes create interference patterns with refracted waves. Except for its far eastern end, the Strait lies within the territorial waters of Spain and Morocco. The United Kingdom claims around Gibraltar on the northern side of the Strait, putting part of it inside British territorial waters. As this is less than the maximum, it means, according to the British claim, that part of the Strait lies in international waters. The ownership of Gibraltar and its territorial waters
Lines of Contravallation of Gibraltar to the territory by land. The lines covered a distance of 950 toises () and were built 1,000 toises () from the Rock of Gibraltar, where the British defences began. This sparked a diplomatic dispute between Britain and Spain. During the negotiations that led to the Treaty of Utrecht of 1713, under which Spain ceded Gibraltar to Britain, the British government sought to compel the Spanish to cede "a convenient quantity of land round Gibraltar, viz., to the distance of two cannon shot ... which is absolutely necessary for preventing all occasions of dispute between the Garrison and the Country