Peter explores the challenges of applying solid-state DC breakers (SSDCBs) in closed multi-bus and ring-based DC systems for maritime microgrids. Unlike AC systems, DC grids face complex fault current behavior, with currents flowing from multiple directions, complicating selective protection and increasing the risk of over- or under-tripping. We discuss advanced solid-state protection solutions for onboard DC grids, including battery string protection and prevention of reverse current during shore charging. Christoph Klie presents spectral impedance-based battery health monitoring up to 150 kHz for continuous, non-intrusive State of Health assessment. Together, these technologies improve the safety, reliability, and efficiency of electric vessels.