Assessing A Risk; Target Acquisition - Raymarine H6 Owner's Manual

81238_1.book Page 66 Thursday, September 16, 2004 2:49 PM
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Effective MARPA operation is dependent on the accuracy of your own ships
heading data, plus Speed over Ground (SOG) and Course Over Ground (COG). The
better the quality of the heading data, the better MARPA will perform. MARPA
will function without SOG and COG data, but target course and speed cannot be
calculated.

Assessing a risk

Each target is displayed as a symbol to indicate its status:
Target is being acquired
Target is safe
Target is dangerous
Target is lost
Each target is monitored to determine if it will be within a certain distance from
your own boat within a certain time. If so, the target is designated as dangerous,
and you are notified with an audible alarm and a flashing on-screen 'MARPA
target (ID No.) Dangerous' warning. Press any key on the Pathfinder unit to cancel
the alarm and remove the warning; however, the target is dangerous symbol
remains displayed. Both the distance (Own Vessel Safe Zone) and the time (Time
to Safe Zone) are selectable.
If a target is lost, it is either because the MARPA software has lost contact with it,
or it has moved out of range. If this occurs, you are notified with an audible alarm
and an on-screen 'MARPA target (ID No.) lost' warning. Press any key on the
Pathfinder unit to silence the alarm and remove the message and lost target
symbol from the screen.

Target acquisition

MARPA target acquisition is only available at radar range scales of up to 12 nm,
although tracking continues at all ranges.
If you change to a smaller range scale, targets may be beyond the range of your
scanner and will be lost. In such cases, an on-screen warning will indicate that the
target is off-screen.
Raymarine H6 - Owner's Manual