With the increasing exploitation of the world's coastal zone and continental shelves, covering a range of applications (waste disposal, civil engineering, resource extraction), new techniques of evaluating the seafloor are constantly in demand. For any new technique to prove economically viable and be widely used it must offer a rapid, inexpensive, and efficient method of data collection. To this end a seafloor geophysical sledge has been developed to measure in situ the seismic wave velocities (shear and compressional) and the electrical formation factor. Data are collected while the sledge is towed along the seafloor with measurements made at discrete points along a profile line. The collected velocity values may be used directly to input into acoustic models or compute the elasticity of the sediment, or the three geophysical parameters can be applied indirectly via empirical relations to predict other in situ physical parameters.