The Department of Defense (DOD) is seeking proposals for the development of low-cost floats for observing interior ocean flows. The objective is to develop and demonstrate a low-cost, expendable ocean float that can be deployed in large numbers to track interior ocean velocities through the reconstruction of Lagrangian pathways. Currently, observing interior ocean flow is challenging, and most Lagrangian information comes only from drifting buoys at the surface. The proposed floats would follow ocean currents in the upper water column and track the floats for up to a month to reveal submesoscale ocean flow features in a regional area. The floats should be designed to have a specific reconfigurable density without active buoyancy control. Phase I involves designing and developing a concept for the floats, while Phase II includes producing prototypes and testing them at sea. The Phase II effort will require an at-sea demonstration of at least five prototype floats. The final phase, Phase III, focuses on finalizing float design, incorporating additional sensor payloads, and exploring commercial applications such as oceanographic research and water quality monitoring. The project duration and funding specifics are not provided in the document. For more information, visit the solicitation link.