Furuno GP-1850DF - Manual (Page 14)

1-8
Installing the thru-hull mount transducer
Transducer mounting location
This type of mounting provides the best performance of all, since the transducer
protrudes from the hull and the effect of air bubbles and turbulence neat the hull
skin is reduced. When the boat has a keel, the transducer should be at least 30 cm
away from it. Typical through hull mountings are shown in the figure on the next
page.
The performance of the video sounder is directly related to the mounting location
of the transducer, especially for high-speed cruising. The installation should be
planned in advance, keeping the standard cable length (8 m) and the following
factors in mind:
• Air bubbles and turbulence caused by movement of the boat seriously degrade
the sounding capability of the transducer. The transducer should, therefore, be
located in a position where water flow is the smoothest. Noise from the propel-
lers also adversely affects performance and the transducer should not be
mounted nearby. The lifting strakes are notorious for creating acoustic noise,
and these must be avoided by keeping the transducer inboard of them.
• The transducer must always remain submerged, even when the boat is rolling,
pitching or up on a plane at high speed.
• A practical choice would be somewhere between 1/3 and 1/2 of the boat's length
from the stern. For planing hulls, a practical location is generally rather far astern,
so that the transducer is always in water regardless of the planing attitude.
Transducer outline drawings
22
120
30
68 87
68
120
28
24
520-5PSD (option) 520-5MSD (option)
Ship's
bow
All dimensions
in millimeters
Figure 1-11 Transducer outline drawings