Efforts to validate, monitor, and verify ocean-based carbon dioxide removal (CDR) will require a rich understanding of the ocean carbon system. Ocean observations anchor this understanding, but we know that some ongoing observations are precariously funded, that data products like SOCAT rely on volunteer effort, that regions essential to our understanding of the ocean carbon system are under-observed, and that some observation data is under-used. This presentation will be a progress report on our efforts to identify and document ocean carbon data flows using systematic literature reviews and examination of ocean data repositories. These data flows are essential to identify what data the scientific community already relies on; what data and observation gaps exist; and what data might be under-used. We examined variables of interest based on GOOS EOVs, including Oxygen (and supporting variables), Stable Carbon Isotopes (and supporting variables), Ocean Surface Stress (and supporting variables), and Ocean Surface Heat Flux (and supporting variables). Commonly observed supporting variables include O2, alkalinity, pCO2, pH, temperature, and near-surface air temperature, humidity, pressure, and wind speed.