Boating and Sailing.pdf - Moja ladja

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Part 4: Nature’s Triple Play: Wind, Weather, and Tides
Large sailboats like this
Pearson 36-footer may
require 5 feet or greater
depth to keep their keel from
touching bottom. Knowledge
of tide heights is critical for
inshore navigation in deepdraft
boats.
(Photo credit: Pearson Yachts)
For sailors, the tide can be a major factor in both speed and course. Because sailboats
travel at relatively slow speeds, proceeding with a strong tide can as much as double their
speed, and traveling against it can cut speed in half.
Boater-ese
Course made good is
the actual course the boat takes,
as it is affected by wind and currents,
as opposed to the course
steered via the compass, GPS, or
LORAN.
Tide Tables
Running at an angle across a tide can also greatly
change the course made good—the tide becomes a vectoring
force that can push you far off course over a period
of hours. (For a closer look at how this works, see
Chapter 14, “Nautical Radio Gear and Procedures and
Your First Longer Cruise.”)
So where do you get this information?
The tide tables, plotted by the National Ocean Service, provide forecasts of tide height
and current data for locations around the world.
The tables come in book form and are available at many boating-gear stores as well as
chart and map stores. The book you want will probably be either Tide Tables, East Coast of
North & South America or Tide Tables, West Coast of North & South America. They sell for
about $15 each from BOAT U.S. and many other sources. Similar volumes, such as Tide