Great Britain. Ministry of Overseas Development (Directorate of Overseas Surveys) Great Britain. Directorate of Overseas Surveys. North Decimal Degree 17.500000. South Decimal Degree 17.2500. East Decimal Degree -88.1667. West Decimal Degree -88.5000. Standard map series designation: Series E755 (D.O.S. 4499).Transverse Mercator projection. Grid: U.T.M. zone 16. Relief shown by 20 m. contour interval and spot heights.