Boating and Sailing.pdf - Moja ladja

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Part 3: Getting from Point A to Point B: Marine Navigation
Vectoring In
If there were no winds or currents, boats could simply head straight for their destination,
like a car traveling down a road, and wind up where the skipper wanted to go.
But boats are greatly affected by both winds and currents, and the slower the boat, the
greater the effects.
Boat Bytes
In crossing the Florida
Current between the
Bahamas and Florida (commonly
but inaccurately
known as the Gulf Stream),
it’s common for slower boats to
be offset by many miles due to
the northward push of the ocean
current measuring 2.5 to 4
knots. Sailboats and trawlers out
of Miami’s Government Cut must
steer southeast to arrive at
Bimini, which is almost due east.
The difference for a 5-knot boat
can be over 30 degrees!
The Least You Need to Know
If you never venture offshore, the offset of wind and
current is less important, but not completely irrelevant.
When you’re heading for a distant shoreline in a lowspeed
boat such as a pontoon rig, and facing heavy side
winds, you may have to steer far above or below your
target to travel directly toward it.
The same is true with strong river currents—set the
boat at an angle into the current, pointing upstream of
your intended landing point, to get to the spot you
want to reach. Those trying to get boats back on trailers
at river ramps soon learn this tactic.
There’s a bit of science to figuring the appropriate vectors
for long ocean crossings. The process is more than
the beginning boater might want to wade through, but
for those who go on to the blue horizons, the current
edition of Chapman’s Piloting (Hearst Marine Books,
1996) has an excellent chapter on how it’s done.
◆ Every prudent skipper carries some type of communications device, allowing access
to emergency services ashore.
◆ It’s wise to plan any extended voyage well in advance, and to study the route both
before you leave and while you’re underway.
◆ Keep track of your position when you cruise, both electronically and via the art of
dead reckoning. Someday, you’ll be glad you did.