Transom Mount Transducer - Raymarine Transducers User Manual

Chapter 1: Overview

Transom Mount Transducer

Acoustic noise is always present and these sound waves can interfere
with the operation of the transducer. Ambient (background) noise
from sources such as waves, fish, rain and other vessels cannot be
controlled. Carefully selecting the transducer's mounting location
can minimize noise generated by the vessel's propeller(s), shaft(s),
machinery, and other echo sounders. The lower the noise level, the
higher the echo sounder gain that can be used, and the better the
Fishfinder's performance.
CAUTION:
To ensure accurate readings, DO NOT mount the transducer in
an area of turbulence or bubbles:
• near water intake or discharge openings
• behind strakes, fittings or hull irregularities
• behind eroding paint (an indication of turbulence)
Choose a location where:
• The water flowing across the hull is smoothest with a minimum of
turbulence and bubbles (especially at high speeds).
• The transducer will be continuously covered by water when the
boat is moving. If the transducer is mounted near the side of the
boat, it may be exposed when the boat is turning.
• The transducer beam is unobstructed by the keel or propeller
shaft.
• There is a minimum deadrise angle.
• There is adequate headroom inside the vessel for the height of the
thru-hull housing, tightening the nuts, and removing the valve
assembly insert.
• Single drive boat - Refer to Figure 1-1 . If your boat has one pro-
peller (outboard or inboard), mount the transducer about 18" (455
mm) to the side of the boat's centerline. To reduce any interfer-
ence caused by air bubbles, choose the side on the downstroke of
the propeller (usually the starboard side).
• Twin drive boat - If your boat has twin propellers (outboard or
inboard-outboard), mount the transducer between the drives near
the centerline of the boat. If the boat will be operated at high
speeds, the transducer may be mounted closer to the centerline of
the hull.
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