Datums - Lowrance GlobalMap 2000 Installation And Operation Instructions Manual

key, press the key next to the "Reset Man Overboard" label on the menu
shown above.
The GlobalMap 2000 doesn't save the Man Overboard position in the
waypoint table. However, it does save the position on the Man Overboard
Information screen.
To add the position shown at the top of Man Overboard Information menu
to the waypoint table, simply press the key next to the "Covert Man
Overboard to Waypoint" label. The unit assigns that position to the first
available waypoint number in the waypoint table. This waypoint can be
edited the same as any other waypoint on the list, including the name,
symbol, and position.
Remember, repeated pressing of the Man Overboard key does not
repeatedly save your present position! The unit only saves the position the
first time the Man Overboard key is pressed. To save a new Man
Overboard position, you must first reset Man Overboard by pressing the
key next to the "Reset Man Overboard" label on the Man Overboard
Information menu.
You can navigate to a waypoint using the Waypoint Recall feature at any
time, however this stops the GlobalMap 2000 from navigating to the Man
Overboard position.
Remember, saving the victim is the primary goal. Try all options to rescue
the person immediately after the accident happens. Training and educa-
tion are also good accident preventative. The Coast Guard has excellent
safety courses. Instruct all members on board your boat on safety
procedures before leaving the dock. Make certain all on board know what
to do before any emergency occurs.

DATUMS

The GPS navigation system relies on complex mathematical calculations
to determine your position based on satellite data and other factors. One
factor is the Earth's shape. Since the Earth is not a true sphere, variations
in the calculations have to be made to accommodate deviations. To make
matters more complex, not everyone uses the same data to determine
what the deviations are. The size and shape of the ellipsoids that are used
to approximate the earth's surface are improved often. This can lead to
errors if your navigation device uses one ellipsoid, while your chart uses
a different one. The term used for these ellipsoids is "Datum."
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