Furuno CI-80 - Manual (Page 8)

4
Tide Difference = 1 - 2 (Movement of layer B based on
layer A)
or
= 2 - 1 (Movement of layer A based on
layer B)
Layer (B)
:Base of measurement
Layer (A)
2
1
Figure 5
TIDE, NAV-TIDE & TIDE DIFFERENTIAL
Tide
(Absolute tide)
Absolute tide can be measured in the ground tracking mode.
:Base of
measurement
Layer A
Fixed
Start of
trip End of
trip
(Moving at 10 kt on ground)
(Moving at 3 kt on ground)
10 NM (1 hour trip)
2
1
Figure 6
Assume that the ship and layer A are moving in the same
direction, and ship’s speeds based on ground (Vg) and on layer
A (Vwa) are measured as;
Vg = 10 kt (Ship’s speed based on ground)
Vwa = 7 kt (Ship’s speed based on layer A).