Mounting Location
Placement Guidelines
CAUTION
: Do not mount the transducer in line with or near water
intake or discharge openings or behind strakes, fittings, or hull
irregularities that will disturb the water flow.
CAUTION
: Do not mount the transducer in line with trailer rollers
or bunks that may damage the transducer’s face.
Choose a Location
• Where the hull is flat or nearly flat, so the transducer beam will
be aimed straight down.
• Where the water flowing under the hull is smooth with a
minimum of bubbles and turbulence (especially at high speeds).
• Where the transducer will be in contact with the water at all times.
• Where the transducer beam will not be blocked by the keel or
propeller shaft(s).
• In a cool well-ventilated area away from the engine to avoid
overheating.
• Away from interference caused by power and radiation sources
such as: the propeller(s) and shaft(s), other machinery, other
echosounders, and other cables. The lower the noise level, the
higher the echosounder gain setting that can be used.
• Where there is working space inside the vessel.
Hull Types
(Figure 1)
•
Displacement hull powerboats
—Locate amidships near the
centerline. The side of the hull where the propeller blades are
moving downward is preferred.
•
Planing hull powerboats
—Mount well aft, on or near the
centerline, and
well inboard of the first set of lifting strakes
to
ensure that the transducer will be in contact with the water at
high speeds. The side of the hull where the propeller blades are
moving downward is preferred.
2
inboard
Figure 1.
displacement hull
Best location for the transducer
stepped hull
outboard and I/O
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Outboard and I/O
—Mount just forward of the engine(s).
Inboard
—Mount well ahead of the propeller(s) and shaft(s).
Stepped hull
—Mount just ahead of the first step.
Installation
Pre-molded Cavity
If the boat has a pre-molded cavity in the hull to receive the
transducer, a metal template is available from the marine dealers
listed on page 3. Order a PM265 Template. This template is the
correct size for all of the models listed on this owner’s guide.
Making a Cavity
1. Using the template (page 4), cut along the
cutting line for hull
cavity
(outermost line). Tape it to the hull at the selected
mounting location.
2. Cut a hole in the hull.
3. Create a strong watertight cavity to hold the transducer.
Dry Fitting
The transducer must be flush with the bottom of the hull for good
performance.
Dry fit the transducer in the cavity before installing.
1. Position the template (page 4) within the cavity. Tape it in place.
2. Using the appropriate drill bits and hole saw, drill holes through
the hull at the marked locations.
3. From outside the hull, thread the transducer cable through the
hole in the mounting cavity (Figure 2). Push the transducer into
the cavity as far as possible.
Measure the gap between the face of transducer and the outside
of the hull (as if the transducer is flush to the exterior hull
surface). This will be the thickness of marine sealant that must
be applied to the cable side of the transducer, plus an additional
3mm (1/8") to fill any empty spaces.
Bedding & Installing
CAUTION
: Be sure the surfaces to be bedded are clean and dry.
1. To ensure that the marine sealant will adhere properly, sand the
area around the holes, inside and outside. Remove any
petroleum residue with a mild household detergent or a weak
solvent such as alcohol.
Figure 2. Dry fitting
Copyright © 2019 Airmar Technology Corp.
transducer
hull
cable fitting
cavity
face
thickness of marine sealant to be applied
to the cable side of the transducer,
plus 3mm (1/8") to fill any empty spaces