47 C.F.R. § 80.753 Signal strength requirements at the service area contour.
Title 47 - Telecommunication
(a) The requirements for reception by a marine VHF shipboard receiver are satisfied if the field strength from the coast station, calculated in accordance with §80.771 is at least +17 dBu above one microvolt. (b) These field strengths, voltages and powers at the receiver input are equivalent: (1) −132 dBW (decibels referred to 1 watt). (2) 1.8 microvolts across 50 ohms. (3) +17 dBu (decibels referred to 1 microvolt per meter). (4) 7 microvolts per meter.
Title 47: Telecommunication
PART 80—STATIONS IN THE MARITIME SERVICES
Subpart P—Standards for Computing Public Coast Station VHF Coverage
§ 80.753 Signal strength requirements at the service area contour.