| You are approaching an island landfall two miles ahead. | | | | Notice that each abbreviation shows slanted letters. |
| You've heard from other sailboat cruising sailors to | | | | Chart makers use slanted lettering on objects that |
| keep clear of the razor sharp coral reefs on each side | | | | change with the wind, tide, or current. To learn more |
| of the entrance. But do you know what these chart | | | | chart symbols and abbreviations, click this link for a |
| symbols would look like on a navigational chart? Boost | | | | FREE download from the Office of Coast Survey. |
| you sailing navigation skills with these five infamous | | | | ==> |
| danger symbols you need to know for safe sailing | | | | 3. Beware of Plus Signs |
| 1. Know Your Shoal Colors | | | | Rocks that are underwater at all stages of the tide |
| Scan your chart for blue or green coloring when you | | | | look like a "plus" sign. You may see these clustered |
| approach land. Chart makers make blues darker when | | | | together or as a solitary symbol. Make sure you |
| the water gets shallower. Use this easy memory key | | | | highlight them so that they stand out on your nautical |
| "Then darker the blue, the more danger to you". But | | | | chart in all light and weather conditions. |
| you will find many charts that show only one shade of | | | | 4. Stay Clear of Plus Signs with Dots |
| blue. | | | | Chart makers add dots onto the four open corners of |
| Highlight the boundary of each shoal that shows | | | | a plus sign if the rock becomes awash--or breaks the |
| depths less that 2 1/2 times your draft. For example, if | | | | water surface--at the low water stage indicated by |
| your small cruising sailboat has 6 feet of draft, you | | | | your chart. In heavy weather, breakers will form over |
| should highlight any shoal water less than 15 feet. | | | | rocks like this. Stay clear to stay safe! |
| Raise this factor as you see fit (to 3 x or 4x draft). | | | | 5. Look for Asterisks that Uncover |
| Look for green tinting along the shoreline. This indicates | | | | At low water, some rocks or small islands--called |
| areas that cover and uncover with the tide. In most | | | | islets--uncover so that part of them becomes visible. |
| cases, these shoals will be invisible at higher stages of | | | | Rocks are shown as asterisks, and islets as small, |
| the tide. Stay well clear of green tinted areas to avoid | | | | squiggly, uneven circles. Look for an underlined height |
| going aground. | | | | near the symbol. This shows how much of the rock or |
| 2. Learn Bottom Abbreviations | | | | islet will be visible at the low water. Some islets show |
| Know the most common two to three letter | | | | as smooth (not squiggly), uneven circles. These islets |
| abbreviations that tell you the type of sea bottom. | | | | are visible at all stages of the tide. |
| These are: | | | | These five chart navigation secrets will get you |
| M = mud | | | | started on your way to learn the most important chart |
| S = sand | | | | symbols and abbreviations for safe sailboat cruising. |
| Rk or Rky = rocks or rocky | | | | That way, you will gain the confidence you need to |
| Co = Coral | | | | keep your sailing crew safe and sound--wherever in |
| Cl = Clay | | | | the world you choose to cruise. |