Section 9: Finding Your Way 105
CHARTS AND MAPS
Maps show you where you can go, but
charts also show you where you cannot
go. Maps indicate roads or land features
and charts indicate features on the water.
Charts show a scaled two-dimensional representation
of the Earth. As a boater, you
must know where you are and the best way
to reach your destination. Charts are vital
to your safe boating.
Charts provide information on
underwater depth, areas of depth changes,
and obstacles or hazards.
• The depth is shown in spot depths in feet,
meters, or fathoms (6 feet equals 1 fathom);
the units are identified on each chart.
• Depth contours are displayed by solid,
dashed, or dotted lines that connect
points of equal depth.
• Natural and man-made hazards are
shown with symbols that are explained on
the chart key or in Nautical Chart No. 1.
As a skipper, you need to be able to
obtain the other information on the charts
that helps you navigate a safe trip, such as:
• Aids to navigation (buoys, beacons, lights,
sound devices)
• Informational notes
• Special zones (restricted areas, anchorage
areas, exclusion zones)
• Various pre-plotted navigation information
(established channels, pre-plotted
courses)
PILOTING
Piloting is directing your vessel safely and
efficiently across the water to a planned
destination. You use navigational skills
and are aided by landmarks and aids to
navigation. The methods change based on
whether you are piloting offshore, near
coastal, coastal, or inland.
• Offshore navigation is different from
coastal or inland because there are no visible
landmarks for reference.
• Coastal and inland areas have the greatest
density of other vessel traffic or man-made
hazards as well as tides, currents, natural
shallows, and isolated hazards. As the skipper,
you are expected to know the waters
in your area. Check with marina operators
and other boaters about any hazards you
may encounter.
When planning a trip on the water,
the natural inclination is to assume you
can travel anywhere you want without having
to follow a road as you would on land.
This common misconception is dangerous
because obstacles both above and below the
surface can cause problems for a vessel. The
planned road for a trip on the water is made
up of a sequence of legs; it is called a route.
Each leg of your planned route is set up for
you to travel a compass direction for a specific
distance.
ELECTRONIC NAVIGATION
When using traditional navigation, a lot of
your effort is used to determine where you
are at various times. You then proceed by
estimating your progress toward your destination
using landmarks, aids to navigation,
and other references to check position. With
electronic navigation equipment, combined
with a global positioning system (GPS), it is
possible to know at anytime where you are
with the touch of a button. You then can use
the traditional methods to verify the accuracy
of the equipment or operator’s proficiency.
The electronics must be set up correctly
to provide accurate information.
GPS
(Global Positioning System)
The GPS is being used more and more as the
primary positioning device for most boaters.
Modern GPS equipment can provide a precise
position on a continuous basis.
• The position is derived from signals from
a series of 28 satellites in orbit around the
earth (more satellites are being launched
by the US and the EU).
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