Marine geophysical surveys using Seabeam, single channel seismic reflection, gravity and magnetic profiling were conducted along the Acapulco Trench (21 degree 30'N-18 degree 00'N) during the Seamat Cruise of R/V Jean Charcot in June-July 1987. The surveyed areas are centered around latitude 18 degree N and 20 degree 30'N across the trench. Detailed surveying was also conducted at the East Pacific Rise (EPR) - Rivera Fracture Zone (RFZ) eastern junction. Unpublished bathymetric data of the Searise Cruise of R/V Jean Charcot conducted at the Western junction of EPR and RFZ in 1980 are also presented.