A unique Sediment Acoustic‐speed Measurement System (SAMS) was developed to directly measure sediment sound speed. The system consists of ten fixed sources and one receiver. In a typical deployment, the SAMS is deployed from a ship that is dynamically positioned. The sources are arranged just above the sea bottom and the receiver is drilled into the sediment with controlled steps by a vibro‐core. The maximal sediment penetration depth is 3 meters. At each receiver depth, the 10 sources transmit to the receiver at different angles in the frequency range of 2‐35 kHz, providing 10 estimates of sound speed through time‐of‐flight measurements from the known source‐to‐receiver geometry. SAMS was deployed three times during the recent Shallow Water Experiment 2006 (SW06) on the New Jersey shelf at 80 m water depth. Preliminary results of sediment sound speed are 1618 ± 11, 1598 ± 10, and 1600 ± 20 m/s at three separate deployment locations. Little dispersion in sediment sound speed was observed. (Work supported by ONR)