With funding support from NSERC and Oceans North NGO, a research consortium led by researchers at the Centre for Earth Observation Science (CEOS), University of Manitoba (UM), carried out an oceanographic research expedition to James Bay and Belcher Islands during July 31 - September 1, 2023. This expedition was the third oceanographic research cruise to James Bay and nearby waters aboard the RV William Kennedy, intended to update our understanding of the oceanography of this system. The first expedition took place in summer 2021 and accomplished oceanographic sampling throughout James Bay as well as deployment of several oceanographic moorings intended to monitor subsurface conditions for year-long periods. During the summer 2022 expedition, the moorings were recovered and sampling was repeated at a number of stations throughout James Bay. The summer 2022 program also expanded oceanographic data coverage to include the waters surrounding the Belcher Islands in southeastern Hudson Bay, which receives outflow from James Bay. During summer 2023, mooring and sampling programs were continued in southern Hudson Bay.