46 CFR §184.404

1. (a)A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface navigation with a radar screen mounted at the primary operating station if:
   1. (1)The vessel is self-propelled;
   2. (2)The vessel has an oceans, coastwise, limited coastwise, or Great Lakes route; and
   3. (3)The vessel carries more than 49 passengers.
2. (b)A ferry that carries more than 49 passengers on a rivers route not within one mile of land must be fitted with a FCC Type Accepted general marine radar system for surface navigation with a radar screen mounted at the primary operating station.
3. (c)The radar and its installation must be suitable for the intended speed and route of the vessel.
4. (d)A vessel operated on a short restricted route need not be fitted with a radar if the cognizant OCMI determines that a radar is not necessary due to the vessel's route and local weather conditions.