This project assesses the vulnerability of marine navigation systems to natural and malicious electromagnetic phenomena, with a particular focus on the beacons and range lights in the aid-to-navigation (ATON) network maintained by the United States Coast Guard. With an adaptive and iterative approach to implementing industry-standard electromagnetic compliance testing, Team 2029 designed a test platform and methodology to assess vulnerability to unwanted currents induced on system power leads. This testing simulates a hazard common to both electromagnetic pulse and geomagnetic disturbances. Results detail frequency-dependent susceptibility for multiple electronic systems, including prototype circuits used for test setup verification and models of ATON devices similar to those in present use. In addition, the team has provided the USCG Research and Development Center with implementation plans for additional testing modalities which could assess vulnerabilities to other EM hazards.