What's the "Bottom" Line?

Let’s imagine you are reading a chart, looking for a nice place to “drop a hook”: (LANDLUBBER translation: anchor).  You see a nice cove on the chart, and then you see some odd letters in that cove.  They might read:  S   (or maybe)  M  (or perhaps) Si .  And that would make you happy.

So THAT's what the "Wd" means on my nautical chart!

So THAT's what the "Wd" means on my nautical chart!

On the other hand, you might see some of these letters:  Rk  (or maybe) Co (or perhaps) Wd! .  And that might make you sad.  Sad enough to seek out another anchorage!

So what in the name of alphabet soup are you reading on the chart?  Answer: the condition of the bottom, or seabed.  Why should you care what is on the bottom?  You probably shouldn’t care – unless you plan to anchor. 

Thus:  S = Sand; M = Mud; Si = Silt.  Pretty good for anchoring as you can sink an anchor into these bottoms and the holding power is great.

However:  Rk = rocky; Co = Coral [huge fines possible if you try to anchor in coral]; and Wd = Weeds.  None of them making a friendly place for your anchor to visit.

Your chart tells you this, and might help you decide if a Bruce anchor, or a plow, or a Danforth anchor might work better – or the chart might convince you not to anchor at all! 

So what’s the “bottom line” to the letters on your chart?  Answer: Giving you enough information for securely attaching your anchor TO the bottom!