Maritime AD(A)S products, the maritime counterpart to automotive advanced driver assistance and automated driving systems, currently lack the structured closed-loop testing methodologies that have become standard in the automotive sector. This report inves tigates whether model basin facilities can help fill that gap by serving as a hardware-in-the-loop component, a concept referred to as Basin-in-the-Loop (BiL) testing. The study focuses on the Maritime Dynamics Laboratory (MDL) at RISE/SSPA Maritime Center. The core finding is that BiL is both useful and technically feasible. It offers genuine value when the system under test depends on accurate hydrodynamic coupling and environmental response, phenomena that simulation inevitably simplifies. The MDL measurement infrastructure already provides the essential building blocks: both measurement systems offer external-facing UDP interfaces capable of bidirectional real-time communication. The main barrier is not missing infrastructure but rather that the existing interfaces have not yet been formally documented and standardized. The report proposes formalizing these interfaces into a documented digital platform specification and outlines a proof-of-concept plan for exercising it in a real test context.