The Open Ocean CTD sensor is a small, low cost, and open source sensor built to collect conductivity data in the harsh arctic ocean environment. Measuring ocean conductivity is a crucial part in determining the salinity of the ocean, allowing researchers to gather data about the impacts of the rapid melting of our glaciers. The main barrier in collecting this data is the high cost of research grade sensors, making it economically infeasible to survey the majority of our oceans. A low cost solution to research grade CTD sensors is a must for large-scale oceanography research, allowing researchers to gather more data at more locations to make more informed inferences about our impacts on our oceans.