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Did You Know?

Buoys mark channels and dangers to navigation (such as rocks and shoals).

A compass rose tells direction.

Lighthouses warn mariners about prominent rocks and peninsulas.

Shipwreck symbols mark sunken ship.

Shoals symbol mark shallow water, sand spits, and rocks.

Sounding numbers tell sailors the water depth.

Cobalt is excited PLAY and LEARN

Search for a Shipwreck!

  • Click on Start.
  • Then, scroll your mouse over the chart and see what you find!
  • When you find something, DRAG and DROP your findings onto the table on the left.
  • When you have all the symbols in place, you’ll uncover further surprises... or skip this activity .

More About Nautical Chart Symbols

  • Aids to navigation 
    Lights, buoys, day marks, and fog signals used by the US Coast Guard to mark channels and warn mariners of dangers such as rocks, wrecks, and obstructions. 
  • Fog signals
    Fog horns, bells, gongs, and whistles are used to tell mariners where they are when it is too foggy or stormy to see lights and buoys. 
    They often warn mariners of specific dangers such as rocks and reefs or bridge abutments.


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