The diving operations associated with Project FAMOUS utilized an advanced deep-diving submersible with many capabilities, including a highly accurate positioning system. As the capabilities and mode of operation of this submersible in the context of a major research project are not well known, the operational techniques are described in some detail. Project FAMOUS dive operations relied upon extensive regional and intermediate-scale surface-ship studies prior to and during the dive period. These provided the basic geological and geophysical context in which the studies by the submersible Alvin were placed. The detailed bathymetric charts provided by the U.S. Navy on the basis of multi–narrow-beam echo-sounding, precision submersible navigation, advanced submersible data logging, and post-cruise processing systems furnished an accurate frame of reference for the dive operations as well as for the subsequent studies of the tectonic and volcanic processes within the rift on a scale not hitherto possible. The integration of the dive data with this and other surface ship information was subject to various difficulties which are discussed. Dive tracks adjusted to the basic frame of reference of the Navy bathymetry, a revised bathymetric chart for the dive area, and sample locations and particulars are provided. The FAMOUS operations furnished, in addition to the scientific results, a much better understanding of the best mode of operation for detailed deep – sea-floor studies that utilize a combination of surface-ship and submersible techniques. The lessons learned during this project are discussed in some detail.