The Phase II FATHOM Prototype System offers the Government an innovatively new, unique open architecture, multi-level and multi-domain physics-based capability that “bridges the gap between technology investment and operational utility by enabling prototype experimentation in an operational scenario.” The FATHOM Prototype System provides an innovative task-based user interface, which includes a reusable platform palette and a training module consisting of user-sustainable tutorials and documentation. With the completion of the Option Year Operational Utility Assessment, the concept has been demonstrated as feasible. Significantly, with some modifications, this same fundamental architecture is extensible beyond the naval undersea warfare domain across the full spectrum of naval missions.