Boating and Sailing.pdf - Moja ladja

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Part 4: Nature’s Triple Play: Wind, Weather, and Tides
In the central west coast of Florida where I live, it’s common for anglers to go kingmackerel
fishing along the beaches in 25-knot winds, as long as the blow comes out of
the east or off the land, which it often does after fall fronts pass through. They find flat
water in close, and it stays fishable out to several miles. The same wind coming from the
west in this area would produce very dangerous water along the beach, because it would
have a fetch completely across the Gulf of Mexico.
The Beaufort Scale
The Beaufort Scale, devised in the 1800s by a British admiral of the same name, is best
known as an indicator of gales and hurricanes. But everybody knows you don’t want to
leave the harbor—or even be around the docks—when winds reach these levels.
The lower levels of the Beaufort Scale are more generally useful to recreational boaters,
not because they rate the winds on a 1–12 scale (with “Force 1” being the lowest wind
speed and “Force 12” the highest), but because they give the usual sea conditions at a
given wind speed. This enables a skipper of moderate experience to have some idea what
he or she will face at various wind speeds. The Beaufort Scale is based on open sea conditions
with a broad fetch. It’s shown in the following table.
Beaufort Wind Scale
Beaufort Wind Speed
Number (in Knots) Description Effect on Water
0 Less than 1 Calm Mirror-calm surface
1 1–3 Light air Scale-like ripples
2 4–6 Light breeze Wavelets, no breaking
3 7–10 Gentle breeze Crests begin to break
4 11–16 Moderate breeze Waves 11 /2–4 feet,
numerous whitecaps
5 17–21 Fresh breeze Waves 4–8 feet, some spray
6 22–27 Strong wind Waves 8–13 feet,
whitecaps everywhere
7 28–33 Near gale Waves 13–20 feet, white
foam, wave streaks
8 34–40 Gale Waves increase in length,
foam blown off sea, sea
streaks white
9 41–47 Strong gale Waves over 20 feet,
limited visibility