Airmar Shorty™ Transducers—P6 - Manual (Page 2)

Mounting Location
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 may disturb the water flow.
CAUTION: Do not mount the transducer where the boat may be
supported during trailering, launching, hauling, or storage to avoid
damaging the transducer’s face.
• The water flowing under the hull must be smooth with a
minimum of bubbles and turbulence (especially at high speeds).
• The transducer must be continuously immersed in water.
• The transducer beam must be unobstructed by the keel or
propeller shaft(s).
• Choose a location 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.
• Choose a location with a minimal deadrise angle, so the
transducer beam will be aimed toward the bottom.
• Choose an accessible spot inside the vessel with adequate
headroom for the height of the housing, tightening the nuts, and
removing any insert.
Model
Minimum Headroom
P6, P7 76mm (3")
Retractable P8, P208 153mm (6")
Boat Types (see Figure 1)
• Displacement hull powerboats—Locate amidships near the
centerline. The starboard 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 starboard side of the hull where the propeller
blades are moving downward is preferred.
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.
Boat capable of speeds above 25kn (29MPH)—Review the
installation location and operating results of similar boats before
proceeding.
• Fin keel sailboats—Mount on or near the centerline and
forward of the fin keel 300–600mm (1–2').
• Full keel sailboats—Locate amidships and away from the keel
at the point of minimum deadrise.
Installation
Hole Drilling
Cored fiberglass hull—Follow separate instructions on page 3.
1. Drill a 3mm or 1/8" pilot hole from inside the hull. If there is a rib,
strut, or other hull irregularity near the selected mounting
location, drill from the outside.
2. Using a 51mm or 2" hole saw, cut a hole perpendicular to the hull
from outside the hull.
P208 flush housing—Use a countersink tool to make a “seat” in
the hull.
3. Sand and clean the area around the hole, inside and outside, to
ensure that the sealant will adhere properly to the hull. If there is
any petroleum residue inside the hull, remove it with either mild
household detergent or a weak solvent (alcohol) before sanding.
Metal hull—Remove all burrs with a file and sandpaper.
Bedding
CAUTION: Be sure the surfaces to be bedded are clean and dry.
Apply a 2mm (1/16") thick layer of marine sealant around the
flange and up the sidewall of the housing that will contact the hull
(see Figure 2). The sealant must extend 6mm (1/4") higher than
the combined thickness of the hull, any washer(s), and the hull
nut. This will ensure there is sealant in the threads to seal the hull
and hold the hull nut securely in place.
Installing
1. From outside the hull, push the housing (and cable if applicable)
into the mounting hole using a twisting motion to squeeze out
excess marine sealant. Align the arrow on the flange of the
housing to point forward toward the bow (see Figure 2).
2. From inside the hull, slide any washer(s) onto the housing.
NOTE: Some installations do not have a washer.
Aluminum hull less than 6mm (1/4") thick—Use an additional
rubbery, plastic, or fiberglass washer. Never use bronze
because electrolytic corrosion will occur. Never use wood
because it will swell, possibly fracturing the plastic housing.
3. Screw the hull nut into place, being sure the notch on the upper
rim of the housing is still positioned forward toward the bow.
Hand-tighten only. Do not over-tighten.
Plastic housing—Do not clamp tightly on the wrench flats
possibly fracturing the housing.
Cored Fiberglass Hull—Do not over tighten, crushing the hull.
4. Remove the excess sealant on the outside of the hull to ensure
smooth water flow under the transducer.
Retractable Models
1. After the sealant cures, inspect the O-rings on the transducer
insert (replace if necessary) and lubricate them with the silicone
lubricant supplied (see Figure 3). The O-rings must be intact and
well lubricated to make a watertight seal.
2. Slide the insert into the housing with the arrow on the top pointing
forward toward the bow. Seat it into place with a pushing twisting
motion until the key fits into the notch (see Figure 2). The arrow
on the top of the insert, the notch, and the arrow on the flange
of the housing will all be aligned. Be careful not to rotate the
housing and disturb the marine sealant.
2
planing hulls
Figure 1.
full keel sailboats
large displacement hulls
small displacement hulls
fin keel sailboats
Best location for transducer
Copyright © 2005 Airmar Technology Corp.
stepped hull
outboard and I/O