A vertical seismic profile experiment carried out at Ocean Drilling Program Site 891 ties the regional seismic reflection data to the drilled and logged section and provides additional velocity data near the frontal thrust. The depth of the frontal thrust is confirmed to be between 425 and 440 mbsf at a two-way traveltime of 4.05 s. Compressional P-wave velocities in the upper 275 mbsf as determined by a walkaway VSP (1883 m/s) are consistent with those measured by in situ wireline sonic logs. Sonic log velocities between 310 and 400 mbsf are bounded by the walkaway VSP (1883 to 1835 m/s) and zero-offset VSP (2193 m/ s) velocities. Below the depth of the drill hole, the walkaway VSP velocities are significantly lower than those determined by stacking velocity analyses on nearby multichannel seismic lines. Shear wave velocities in the upper section, as measured by the walkaway VSP, are about 340 m/s.