BUOYS

Small shapes on a short stalk. Red and green mark the sides of a channel, yellow marks a special area, red and white marks mid-channel. The shape shows whether it is a can, a nun or a pillar.

LIGHTS

A magenta flare beside a buoy or beacon marks a light. Text such as "Fl G 4s 15ft 5M" reads: flashing green, one flash every 4 seconds, 15 feet above the water, visible 5 nautical miles.

DEPTHS

Loose numbers are soundings: the depth at that spot at the chart's datum. The units are printed on the chart itself, so check before trusting them. Lines joining equal depths are contours, and shallow water is shaded.

AREAS

Dashed or dotted boundaries with a magenta tint mark anchorage areas, restricted or prohibited areas, cable and pipeline areas, and dredged channels. The label inside says which.

LAND AND SHORE

Piers, jetties and breakwaters are drawn in outline. Tinted bands along the shore are the area that dries at low water.

FULL LIST

Every symbol is in NOAA’s U.S. Chart No. 1, free to download.

Not for navigation. Use official charts and up-to-date Notices to Mariners.