During the period prior to the formation of an independent surveying service as part of the Royal Navy, the making of hydrographic surveys was a haphazard affair often dictated by circumstances rather than as part of a well ordered and integrated scheme. Ordinary serving officers of the Navy were encouraged as part of their duties to obtain information relating to depths, sea-marks, time of tides, setting of the currents, &c.; especially when on a foreign station. In home waters, although the same directive applied, the Admiralty authorities also sought to improve the standard of charting by helping, and in some cases commissioning, private individuals to carry out hydrographic surveys of various parts of the coast. The valuable contribution made by these ‘amateurs’ is shown by the number of charts they produced, particularly during the first half of the eighteenth century. Although the printed charts have survived as a tangible record of their labours, little is known of the methods they employed and the difficulties that confronted them. In the case of Lewis Morris, however, the fact that he was an antiquary, literary scholar, philologist and mineralogist and attained greater fame in fields other than surveying, has meant that a considerable amount of his manuscript material has survived.1 From a surveying standpoint this material includes a number of letters and memoranda sent by Morris to the Admiralty and other interested persons, the original manuscript plans of his survey of the Welsh Coast and a rough survey notebook in which he jotted down his observations while out in the field. The latter is probably unique as, for obvious reasons, field notebooks are inevitably destroyed as the finished product emerges. It is thus possible to obtain a well documented and comprehensive picture of the way in which a zealous individual like Morris set about the stupendous task of surveying hundreds of miles of coastline and inshore waters in the interests of safer navigation.