A brief guide to judging water depth visually

Judging water depth based on color is an imperfect science, but it is a good skill to have.

One of the most important marine instruments you can have on board is a depth finder, whether it's an advanced transducer or similar device. Sometimes it's an independent instrument and other times a part of your chartplotter or GPS. In any case, these devices help you figure out the clearance between the end of your keel and the bottom of the body of water where you're boating.

But depth finders and transducers can only help you so much. They can't tell you how deep the water is a quarter mile in front your bow or off to the side. They also don't necessarily give you an accurate reading if the water is too deep. It all depends on the power of the sonar beam they're transmitting.

At Sail Magazine, writer Connie McBride has a good rhyme that is easy to remember and can help you better judge water depths visually:

Brown, brown, run aground
White, white, you just might
Green, green, in between
Blue, blue, sail on through

Simply put, when the water in front of you is a light brown color, it's best to avoid it in the event that you scrape your hull or run aground. White-colored water could mean that there is sand reflecting sunlight back to the surface, though it may be deep enough that you don't have to worry about hitting anything. Green water typically indicates that there is grass on the surface, but it could still be deep enough that you can sail over it safely. Blue water means you're good to go!

With a more powerful marine transducer, you can judge depths more effectively and avoid running aground. Shop at ePal today for our latest deals on tranducers and other equipment!

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>