The University of Alaska Fairbanks (UAF) requests funds for oceanographic instrumentation that are needed to carry out NSF-supported scientific research on board the R/V Sikuliaq, a vessel operating as part of the U.S. Academic Research Fleet (ARF). The specific suite of instrumentation requested includes a shallow water multibeam system which would significantly enhance the vessel’s ability to support a wide range of oceanographic and environmental research; a fisheries sonar suite that would replace an aging system; and a new sub-bottom profiling system processing unit that has reached end-of-life. The combined purchase and installation of these systems would benefit from a planned shipyard in 2026 and would ensure the vessel maintains its high-level capabilities to support NSF-funded research. The principal impact of the present proposal is under Merit Review Criterion 2 of the Proposal Guidelines (NSF 23-525). It provides infrastructure support for scientists to use the vessel and its shared-use instrumentation in support of their NSF-funded oceanographic research projects (which individually undergo separate review by the relevant research program of NSF). The acquisition, maintenance, and operation of shared-use instrumentation allows NSF-funded researchers from any US university or other organization access to well-maintained, high-quality, calibrated instruments for their research. It ensures the collection of high-quality oceanographic data in support of science,