Similar to utility grid and other terrestrial microgrids, aircraft electric power systems and shipboard microgrids have their own power generation, distribution, utilization and generation storage. The rapid development of power electronics technology has allowed the converters to operate at DC voltage levels required for transmission, distribution and consumption. However, the coordination among power electronic converters can lead to malicious intrusions that aim to manipulate microgrids' operation and cause deviation from their mission-critical objectives. Such manipulations may lead to disturbances during motion, thus posing serious risks to passenger lives and cargo. The disturbances can also affect operations in critical sectors such as commercial transportation and defence, which may directly influence the global economy and national security. This chapter overviews the industrial security measures considered for microgrids in mission-critical applications, such as those found in electric aircrafts and shipboard power systems, with further insights on vulnerable areas, which can be exploited by stealthy attackers.