12 seamanship secrets
topmark—a lollipop shape on a pole sticking out of the top of the buoy. Pie-pan
shaped mooring buoy symbols are always black.
LIGHTED BUOYS
The symbology for lighted buoys is the same as that for unlighted buoys
except that a large magenta (light purple) disk covers the swing circle. Only
lighted diamond-shaped buoys show a purple disk.
DAYBEACONS
Small triangles or squares represent unlighted dayboards atop pilings called
daybeacons. These symbols may be white, green, or red. The shape and color
of a dayboard is the same as its charted symbol.
LIGHT STRUCTURES
Fixed lighted structures—structures that don’t move, such as lights or light-
houses overlooking the sea—show a magenta teardrop shape with a black dot
on the tapered end. The dot represents the aid’s exact position. Cartographers
sometimes enclose light symbols with a squiggly, irregular circle to indicate
that riprap (broken rock, shale, or concrete slabs) surrounds the light. This
material helps cut down on erosion from waves pounding onto the lighthouse’s
foundation. Give such lights a wide berth.
ELECTRONIC AIDS
Larger fl oating or fi xed aids sometimes carry a radar beacon, called a RACON.
Pulses transmitted from your radar trigger the RACON, and an image of a
Morse code letter appears on your radar receiver. For instance, the Dry Tortugas
Lighthouse carries a RACON with the Morse code symbol for K (—.—). When
activated, a long dash, dot, and long dash appear on your radar display, identify-
ing the exact position of the light. It’s possible to pick up RACON signals up to
17 miles away.
lighted buoy daybeaconslighted mooring buoys
(light symbol can face any direction)left; light structure (any size);
right; light structure with riprapChart symbols for various lighted and unlighted buoys.