47 CFR § 80.1179
On-board repeater limitations
February 16, 2021
When an on-board repeater is used, the following limitations must be met:
(a) The on-board repeater antenna must be located no higher than 3 meters (10 feet) above the vessel's highest working deck.
(b) Each on-board repeater must have a timer that deactivates the transmitter if the carrier remains on for more than 3 minutes.
[51 FR 31213, Sept. 2, 1986, as amended at 58 FR 44954, Aug. 25, 1993]