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Wide‐angle ocean bottom seismic data and single‐channel seismic reflection data were collected in June 1992 over an area where gas hydrates are thought to be extensive on Blake Ridge, offshore South Carolina. Wide‐angle reflections were observed on four Woods Hole Oceanographic Institution ocean bottom hydrophones at offsets up to 15 km. Results from traveltime inversion show that the bottom simulating reflector (BSR) that marks the base of the hydrate stability field lies 400–500 m below the seafloor and is overlain by a 200‐ to 300‐m‐thick layer of average velocity 1.9 km s⁻¹. There is no evidence for significant lateral velocity variation associated with lateral changes in BSR character. Ray‐tracing calculations show that the observation of the BSR out to large offsets (7 km) constrains the maximum vertical velocity gradient to about 0.5 s⁻¹. Amplitude‐versus‐offset (AVO) analysis was performed for …