Furuno GP-3500F Installation Manual page 16

Thru-hull mount transducer mounting dimensions (millimeters)
Acceptable transducer mounting locations
22
120
120
28
30
68
68
520-5PSD
DEEP-V HULL
Position 1/2 to 1/3 of the hull
from stern.
15 to 30 cm off center line
(inside first lifting strakes.)
HIGH SPEED-V HULL
Within the wetted bottom area
Deadrise angle within 15°
Suitable transducer mounting locations
9
24
90 Unit: mm
520-5MSD