My yacht was in the vicinity of a wind farm when all our electrics cut out. The equipment eventually responded to pressing of ON switch.
Five other vessels in the area had similar experiences. Electro magnetism? Too much of a coincidence. On return journeys none of us had a problem.
We passed this report (disidentified) to the appropriate manager of the MCA. He contacted the wind farm developers who advised that they have no equipment that could cause such failure.
We would be interested to hear of any similar experiences.