New approaches are developed to use peak penetration-induced pore pressure magnitudes to in-dex profiles of in situ permeability. These methods potentially enable permeability profiles to be determined from continuous sounding by cone penetrometers, and from freefalling marine penetrometers that self-embed into seafloor sediments. Solutions are developed for the unsteady and partially-drained, fluid pressure field that develops around a volumetric dislocation that represents a penetrometer either advanced at constant rate, or decelerating as it self-embeds after freefall. Inertial effects are ignored. These solutions provide a consis-tent framework to view the penetration process, and enable penetration-induced pore pressures to be repre-sented in non-dimensional form, and related to conventional sounding indices inclusive of tip resistance, Q t , friction factor, F r , and pore pressure ratio, B q , among others. These relationships are used to define perme-ability magnitudes in the intermediate range where response is partially drained.