In the Marsden Square Grid System, or its derivations - and this is the system that most national and international oceanographic data acquisition centres employ - the information is located geographically for statistical purposes by means of a grid consisting of 10°, 5° or 1° " squares ". The system, an early one dating from 1850, has three major disadvantages, and this has meant that its numbering principle cannot be used for a grid whose smallest lattice is less than 1° of latitude by 1° of longitude. [NOT CONTROLLED OCR]