Do you know what a pie-pan shaped chart symbol indicates on your nautical chart or chart plotter? Or the difference between an exclamation mark and diamond symbol? How can you tell whether a nautical chart symbol means that an aid to navigation floats or doesn’t float?
Check the symbol lettering
Slanted letters next to a symbol tell you that the object moves with the wind, tide, and current. Buoys are anchored to the sea-bottom with a short scope of chain. The chain attaches to a concrete block.
Vertical letters are used next to symbols of structures that stand straight and tall no matter what the marine weather. These include daybeacons, lighted beacons, lighthouses, and prominent objects along the shore (tanks, church spires, antennas).
Chart cartographers use specific symbols that indicate unlighted buoys, lighted buoys, daybeacons, or light structures. Use these five tips to guide you:
1. Daybeacon Day Shapes
Daybeacons are unlighted, fixed structures used in places where buoys are not practical. They often mark the edges of shoal water. On the nautical chart, a daybeacon symbol may be square or triangular.
2. Diamond Buoy Body Anatomy
Most buoy symbols on navigational charts look like small diamonds. They may show one or more colors, or a vertical or horizontal line that slices the buoy symbol down the middle. Use the small open circle at the base of the diamond to determine the buoy position.
Solid black pie-pan-in-profile shaped symbols warn of a large mooring buoy. These are huge, steel disks with a mooring ring-bolt on top, used by large ships. Keep well clear of these symbols to avoid the dangers of a boat-to-ship confrontation.
4. Exclamation Points to Safety
Fixed light structures are indicated by a teardrop shape with a black dot at the base. The dot shows the exact position of the light. The teardrop and dot look similar to an exclamation point. Look for reliable light symbols for safer sailing navigation.
5. Circle and Dot Dependability
Light symbols show a dot, which tells you that they are fixed structures unaffected by wind, tide, or current. Buoy symbols show a small open circle, which tells you that they are floating and can swing on their chain when wind, tide, or current change. Buoys can drag–just like a small cruising boat–in rough weather. Use caution when buoys are your only navigational aids.
Learn to recognize the most common nautical chart symbols used on navigation charts throughout much of the cruising world. This will boost your sailing navigation skills to help you make the best decisions for the safety of your sailing crew.
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