Numerous autonomous underwater vehicles (AUVs) are operating with very precise swath bathymetric mapping systems in ocean depths to 3<th>000 m and greater. Although these systems acquire data from positions known to a few centimeters accuracy with respect to the vehicle position, the positioning of the AUVs is generally no better than tens of meters at great depths. Although not yet assembled into an operational system, the technology now exists to acoustically navigate an AUV to within a 10 cm in x, y, and z. This begins by establishing active reference positions on the seafloor, known to within a few centimeters absolutely, using acoustic mirror transponders that transmit and receive streams of pulse coded signals from an accurately navigated surface vessel. These bottom reference positions can then be the core of a long baseline acoustic navigation system which, when coupled with constant monitoring of oceanographic conditions to calculate pressure corrections for depth measurements, will provide 10-cm navigation accuracy for the mapping AUV. Implementation of this technology will enable observational mapping of highly seismic areas where frequent earthquakes can cause many meters of deformation of the seafloor, and can generate massive tsunamis.