9732353 Smith Scripps Institution of Oceanography will continue development of a deep sea autonomous vehicle (AUV) capability that will provide a platform for a variety of sensors of interest to the ocean science community. This proposal builds on the work and experience gained during development of the ROVER vehicle. The project involves development of an advanced ROVER II, with major modifications in the instrument assembly and payload configuration to accommodate an optical acoustic imaging system and a sequential multiple coring system. These new sensing and sampling systems also will require modification of the central controller package. ROVER II is envisioned to be an autonomous bottom-transecting instrument for making time-series measurements of phytopigmnet fluorescence and acoustically detectable sediment structure. This vehicle addresses questions of significant interest and concern to a broad spectrum of marine biogeochemists and benthic biologists. Time-series measurements of the responses of benthic communities to pulsed Particulate Organic Matter (POM) delivery, and the resultant distribution and fate of organic matter within surface sediments, is critical to our understanding of the role of benthic-pelagic coupling in basin- wide chemical cycling budgets.