46 C.F.R. § 108.717
Radar
Each self-propelled unit of 1,600 gross tons and over in ocean or coastwise service must have—
(a) A marine radar system for surface navigation; and
(b) Facilities on the bridge for plotting radar readings.
Each self-propelled unit of 1,600 gross tons and over in ocean or coastwise service must have—
(a) A marine radar system for surface navigation; and
(b) Facilities on the bridge for plotting radar readings.