A nearshore site investigation in a deep marine clay was performed in British Columbia, Canada. Investigation boreholes and seismic piezocone penetration test (SCPTu) soundings, including both seabed deployed and top push tests, were advanced to depths of greater than 135 meters below mudline. This paper presents the interpretation of the SCPTu data together with the results of laboratory testing on thin-wall (intact) tube samples from adjacent companion boreholes. Laboratory testing included index tests, consolidation tests, consolidated Direct Simple Shear (DSS), K0 Consolidated Undrained Triaxial Compression tests (K0CUTXC), and combined Resonant Column Torsional Shear (RCTS) tests. The results of the laboratory testing aided the interpretation of the SCPTu data including the development of site-specific correlations to parameters such as shear wave velocity and undrained shear strength.