The concept of a free-fall penetrometer was initially tested in the laboratory using a standard 10 cm2penetrometer on different soil targets. However, the penetrometer was structurally inadequate for use at sea. A new version with a 45 cm2(nominal) cross section was redesigned and successfully tested during sea trials. Subsequent laboratory tests were conducted in the static and free-fall modes using the standard 10 cm2and the 45 cm2penetrometers, The development of the penetrometer and analysis of some of the results are presented in this paper. Further sea trials are scheduled for May 1981.