Furuno GP-150-Dual, Operator'S Manual, Page: 43 / 130

5. SETTING DESTINATION
5-7
5.4 Finding Range and
Bearing Between Two
Points
Selecting course sailing method
The range and bearing to a destination can
be calculated two ways: Great Circle or
Rhumb Line. However, cross track error is
calculated in rhumb line only.
Great Circle: The great circle courseline is
the shortest course between two points on
the surface of the earth. (Imagine stretching a
piece of yarn between two points on the
earth.) However, this course requires
frequent change of heading to follow course
faithfully.
Rhumb Line: The rhumb line courseline is
the straight line drawn between two points on
a nautical chart. This course does not require
frequent changes of heading however it is not
the shortest since it follows the earth's
curvature.
1) Press
MENU ESC , 9 and 1 to display the
PLOTTER SETUP menu.
PLOTTER SETUP
Bearing REF
AUTO
(07
°
W)
MAN
(00
°
E)
ENT:Enter
MENU:Escape
Memory Apportion
Mag Variation
True
TRK = 1000 / 2000Pt
MAG
RL
GC Calculation
User defined #1 SOG
User defined #2
COG
User defined #3 RNG
User defined #4 BRG
Figure 5-20 PLOTTER SETUP menu
2) Press or to selection Calculation.
3) Press or to select RL (Rhumb Line)
or GC (Great Circle).
4) Press the NU/CU ENT key.
5) Press the MENU ESC key.
Calculation procedure
You can find the range and bearing between
two points by two waypoints or two latitude
and longitude positions.
1) Press
MENU ESC and 5 . The MANUAL
CALCULATION menu appears.
MANUAL CALCULATION
: N/S, E/W
ENT : Calculation
: Cursor
MENU : Escape
Waypoint No. From
°
. ’N
° .
’E
To Waypoint No.
°
. ’N
° .
’E
Trial Speed : AUTO MAN
(
.
kn)
TTG: D H M
RNG: . NM BRG: .
°
Figure 5-19 MANUAL
CALCULATION menu
2) Choose two points by one of the methods
below.
Latitude and longitude positions
1) Press
.
2) If necessary press to switch from
North latitude and to South latitude vice
versa.
3) Key in latitude.
4) If necessary press
to switch from West
longitude to East longitude and vice versa.
5) Key in longitude.
6) Press
.
7) Repeat 2-5 to enter other point.
Waypoints
1) Key in first waypoint number (000-999).
(000 is reserved for own ship position.)
2) Press twice.
3) Key in other waypoint number (000-999).
4) Press
to shift the cursor to the Trial
Speed line.
5) Press or to select AUTO or MAN.