Electromagnetic field measurements at 60 Hz in the sea near Montauk Point, NY, and New London, CT

The 60-Hz electromagnetic fields in the Atlantic Ocean off Montauk Point, NY, and from Block Island Sound to the harbor in New London, CT, have been measured to determine the levels of interference to an extremely low frequency (ELF) receiver. Such data are needed to specify how close to the coastline an ELF receiver can come before 60-Hz external interference will degrade system performance. The data indicate that degradation to the ELF receiver from 60-Hz external interference will not occur offshore, but may occur within the confines of New London Harbor.