47 C.F.R. § 80.217
Suppression of interference aboard ships
(a) A voluntarily equipped ship station receiver must not cause harmful interference to any receiver required by statute or treaty.
(b) The electromagnetic field from receivers required by statute or treaty must not exceed the following value at a distance over sea water of one nautical mile from the receiver:
| Frequency of interfering emissions | Field intensity in microvolts per meter |
|---|---|
| Below 30 MHz | 0.1 |
| 30 to 100 MHz | .3 |
| 100 to 300 MHz | 1.0 |
| Over 300 MHz | 3.0 |
Deliver not more than the following amounts of power, to an artificial antenna having electrical characteristics equivalent to those of the average receiving antenna(s) use on shipboard:
| Frequency of interfering emissions | Power to artificial antenna in microwatts |
|---|---|
| Below 30 MHz | 400 |
| 30 to 100 MHz | 4,000 |
| 100 to 300 MHz | 40,000 |
| Over 300 MHz | 400,000 |