Report: Brett, CP. 1981. Cruise Report on Project 81/04. A Regional Geophysical Survey in the Northern North Sea. (IGS Report No 120) The primary objectives were to survey the Fladen sheet area of the IGS 1:250000 map series and to run seven north-south lines to complete the coverage of the Forties and Cod shhet areas. A secondary objective was to complete a gravity survey.