The best possible program for geotechnical soils exploration involves a blend of rotary drilling, undisturbed sampling, laboratory testing, in-situ field tests, and geophysics, all taken within the context of engineering geology. Yet, this is only viable when sufficient allocations of time and funds are available, namely large or critical projects. Therefore, for routine site investigations, the use of hybrid geotechnical-geophysical methods should be adopted, including the seismic piezocone test (SCPTù) and seismic dilatometer (SDMTà), since they collect as many as five independent readings with depth, thereby optimizing the information gathered in an efficient, expeditious, and economical manner.