Here’s another great cruising tip from our friend Capt. John of skippertips.com…
Combine GPS, visual, or Radar for sailing navigation and you could come up with a triangular position called a “cocked hat”. You might think that you lie in the center of this triangle. But that may not be the best choice for sailing safety. Discover one fast and easy sailing tip that will help keep your small sailboat in safe water.
Remember those movies or old TV series about Revolutionary War guys and gals? You could always tell them by the funny triangular shaped hats atop their heads.
In navigation, we use a term called “cocked hat” to describe a common triangular-shaped fix that results in the real world of visual, radar, or GPS/visual combination navigation.
Look in most books on navigation and you see three lines of position (LOP) or circles of position (COP) that cross at a perfect, precise point. That happens once in a while–in particular on aircraft carriers or big ships, but not in the real world of small sailboats on a heel, pitch and roll. Sure, you can take two LOP or COP and have a good idea of your position.
But a third LOP or COP confirms and strengthens a position in a big way. For example, your GPS lat and long always gives two LOP that cross at a ninety degree angle. Add a third visual or radar observation and you have great confirmation, or do you?
The tighter the “cocked hat”, the more reliable the fix in most cases. So where do you place your dot in on a “cocked hat? With a small, tight triangle, you might place your position dot in the center of the triangle.
But larger triangles require more care.Note in the illustration that the three plotted LOP result in a large triangular “cocked hat” (yellow shaded area). Two LOP cross at each of the three corners.
If in doubt, dot that corner that lies closest to danger. in the illustration, we place our position at that corner of the cocked-hat nearest the shore. Take action to turn toward safer water. Continue to update your position through other methods of sailing navigation.
Use easy sailing navigation tips like these for safer sailing worldwide. Keep your sailing crew or partner safe and sound–wherever you choose to sail or cruise!