Initially constrained by available techniques surveys were undertaken in shallow and protected areas, progressively moving into deeper and more exposed waters.

The beginning of offshore work was heralded in 1966 by the examination of aeromagnetic anomalies in Loch Ewe and the Moray Firth using a towed magnetometer and shallow seismic profiling system. In the same period, scuba-diving geologists from the Land Survey mapped small areas of Carboniferous outcrop off eastern Scotland.

The following year reconnaissance survey work began in the Irish Sea and continued in 1968, together with work in the Sea of the Hebrides and a detailed study of the Humber Estuary. The first Continental Shelf Unit was formally established in 1967, followed by the Marine Geophysics Unit in 1968 and a second geological unit in 1969.

The United Kingdom was the first country in the world to completely map its continental shelf. This work was first started in 1965 In the early days of the Marine Operations Unit, Then three departments. The mapping took over ten years to complete and was finally finished in 1986. This however was not the end of Marine Operations far from it this had seen the birth of a new industry and a new area of interest for many geologists. Marine Operations began to design and develop many of it own subsea sampling tools to fulfil the science needs.

The first dedicated sampling ship the MV Whitethorn was charted for five years in 1970, this vessel was operated for eleven months of the year.