chart and publication secrets 21
- Scroll down to the latest LNM (sorted by month).
- Click on the latest notice. Th e fi rst two numbers indicate the week
of the year; the last two indicate the year. - Save or print the pdf fi le.
Free Code-Breaker for 36,000 Mariners’ Friends
The U.S. Coast Guard maintains about 36,000 light and unlighted aids to
navigation in the United States and its possessions. Your chart describes the
major characteristics of each buoy, beacon, and light.
When making landfall or sailing in unfamiliar waters, you’ll need more
detailed information. The Coast Guard publishes six volumes of Light Lists,
available online and updated frequently. Download any volume free of charge
from the Coast Guard Navigation Center site (see steps below). To understand
what information the Light Lists include, let’s look at an example.
We’re planning a coastal cruise from Miami to the Chesapeake Bay.
Chesapeake Light, a prominent offshore light structure, marks the entrance
to the bay. On our chart, the description next to the symbol reads:
CHESAPEAKE LIGHT
117' Fl (2) W 15s 19M HORN
RACON: N (-.)What We Know from This Description
Q Th e light is 117 feet above mean high water (MHW).
Q Th e light fl ashes in groups of 2, with a total period of light and dark
of 15 seconds.
Q Th e nominal range of the light is 19 nautical miles. (To see it at that range on
a clear evening, however, we would have to be watching from 31 feet above
the water. We can learn this by consulting a distance to horizon table, found
in Appendix I. We will discuss these methods in Chapter 4).
Q Th e light carries a horn signal.
Q If we have radar, we could receive a signal from the RACON. Th is will
paint an image on our radar display shaped like the Morse code symbol
for N (long fl ash–short fl ash).
What We Still Need to Find Out
Q What is the color and shape of the physical structure?
Q What is the interval of darkness between fl ashes?
Q How oft en does the horn sound, and for how long?