Furuno CI-68 - Manual (Page 64)

PRINCIPLE OF OPERATION
AP-8
Absolute Tide = (1) – (2)
Fixed
Layer (A)
: Base of
measurement
1
2
Tide Differential
Tide differential is a relative movement of tides at different depths, layer (A) and layer (B).
To calculate tide differential, the following two data are used:
1) Ship’s speed and course based on layer (A)
2) Ship’s speed and course based on layer (B)
Tide differential between two layers is, then, given as a difference of these two speed
vectors.
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
2
Layer (A)
1