Airmar P65 User Manual

INSTALLATION INSTRUCTIONSOWNER’S GUIDE &

Transom Mount with Integral Release Bracket

Transducer or TRIDUCER® Multisensor

Model: P65

Follow the precautions below for optimal product
performance and to reduce the risk of property
damage, personal injury, and/or death.

WARNING: Always wear safety goggles and a dust

mask when installing

WARNING: When the boat is placed in the water,

17-293-01 rev. 02 04/12/11

immediately check for leaks around the screws and
any other holes drilled in the hull.

CAUTION: Bracket protects the sensor from frontal
impact only.

CAUTION: Never pull, carry, or hold the sensor by the
cable as this may sever internal connections.

CAUTION: Never strike the sensor.

CAUTION: Never use solvents. Cleaners, fuel, paint,

sealants, and other products may contain strong
solvents, such as acetone, which attack many plastics
greatly reducing their strength.

IMPORTANT: Please read the instructions completely
before proceeding with the installation. These
instructions supersede any other instructions in your
instrument manual if they differ.

Record the information found on the cable tag for future reference.

Part No._______________Date___________Frequency__________kHz

Mounting Location

CAUTION: Do not mount in an area of turbulence or bubbles:

near water intake or discharge openings; behind strakes, struts,
fittings, or hull irregularities

CAUTION: Avoid mounting the sensor where the boat may be
supported during trailering, launching, hauling, or storage.

• For the best performance, the sensor must be in contact with
smooth water. To identify an area of clean water, observe the
water flow off the transom while the boat is underway.

• Allow headroom space above the bracket for it to release and
rotate the sensor upward.

• Mount the sensor as close to the centerline (keel) of the boat as
possible to ensure the sensor remains in the water when the
boat is turning.

• Single drive boat—Mount at least 75 mm (3") beyond the

swing radius of the propeller (see Figure 1). The starboard side
where the propeller blades are moving downward is preferred.

• Twin drive boat—Mount the sensor between the drives.

Applications

• Not recommended for boat with large inboard engine(s).

• Designed for high speed operation up to 55 kn (63MPH)

• Vertically orients sound beam on hull with deadrise angle up to 30°

• Adjusts to transom angles from 3

° –20°

Tools & Materials

Safety goggles
Dust mask
Pencil
Screwdrivers
Electric drill
Drill bit, hole saw or spade bit for:

Bracket holes 4mm, #23, or 9/64"
Fiberglass hull chamfer bit (preferred), 6mm, or 1/4"
Transom hole (optional) 20mm or 13/16"

Cable clamp holes 3mm or 1/8"
Masking tape
Straight edge
Marine sealant (suitable for below waterline)
Zip-ties
Water-based antifouling paint (mandatory in salt water)

75mm (3")
minimum beyond
swing radius

Figure 1. Mounting location on single drive boat

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slope of hull

parallel to
waterline

Align bottom of the sensor
with bottom edge of transom

Figure 2. Bracket position

Pretest

Connect the multisensor to the instrument and spin the
paddlewheel. Check for a speed reading and the approximate air
temperature. If there is no reading(s) or it is inaccurate, check the
connections and repeat the test. If there is still no reading(s) or it
is inaccurate, return the product to your place of purchase.

Plastic Shim

• If you know the transom angle of your boat (see Figure 3):

• Standard transom (13° transom angle)—The bracket is

designed for a standard 13° transom angle, so the shim is
not needed for this installation.

• High Speed Boat—If your boat is capable of speeds above

30kn (35MPH), install the bracket with the shim, tapered end
down. This ensures that the paddlewheel will be immersed at
high speeds.

• Stepped transom and jet boats (3° transom angle) —Use

the shim with the tapered end down.

• Small aluminum and fiberglass boats (20° transom

angle)—Use the shim with the tapered end up.

• If you do NOT know the transom angle of your boat:
To determine if the shim is needed, position the sensor at the

selected location. Using a straight edge, sight the underside of
the sensor relative to the underside of the hull. The trailing edge
of the sensor should be 1–3 mm (1/16– 1/8") below the leading
edge of the sensor or parallel to the bottom of the hull (see
Figure 3).

Attaching the Shim

Align the posts on the shim with the two holes in the bracket.
Snap the shim into place.

Installation

CAUTION: Do not position the leading edge of the sensor lower

than the trailing edge because aeration will occur.

CAUTION: Do not position the sensor deeper into the water than
necessary to avoid increasing drag, spray, and water noise and
reducing boat speed.

CAUTION: To prevent drilling too deeply, wrap masking tape
around the bit 22mm (7/8") from the point.

CAUTION: Fiberglass hull—Minimize surface cracking by
running the drill in reverse until the gelcoat is penetrated.

Assembling, Positioning, & Hole Drilling

1. Insert the sensor’s mounting posts into the slots on the back
TOP of the bracket. Rotate the BRACKET down until the parts
snap together.

2. At the selected location, position the bracket and sensor so the
bottom of the sensor is even with the bottom edge of the
transom (see Figure 1). Being sure the bottom of the sensor is
parallel to the waterline, lightly trace the outline of the bracket
on the boat transom with a pencil (see Figure 2).

3. Remove the sensor from the bracket by inserting the blade of a
screwdriver between the bottom of the bracket and the sensor.
Then pry upward.

4. Holding the bracket in place over the outline you have drawn,
lightly trace the three slots. Draw an “X” in each slot to mark the
screw hole 6mm (1/4") from the bottom in slots 1 and 3, and
6mm (1/4") from the top in slot 2 (see Figure 2). This will allow
you to adjust the bracket up or down. Do not mark the screw

holes at the extreme ends of the slots.

5. Using a 4mm, #23, or 9/64" bit, drill a hole 22mm (7/8") deep at
the locations marked for the screw holes (see Figure 2).

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Mounting & Adjusting

1. Apply a marine sealant to the threads of the three #10 x 1-1/4"
self-tapping screws to prevent water seepage into the transom.
With the sensor attached to the bracket in the “up” position,
screw the bracket to the hull. Do not tighten the screws

completely at this time.

2. Lower the sensor until it snaps into place.

3. Using the vertical adjustment space on the bracket slots, slide
the sensor up or down to provide a projection of 3mm (1/8")
(see Figure 4). Using the straight edge, sight the angle again to
ensure that it is correct (see Figure 3). When you are sure the
hull projection and sensor angle are correct, use a pencil to
mark the hull with the bracket’s exact location.

4. Release the sensor upward. Tighten the screws. Snap the
sensor down into the operating position.

13° transom angle

parallel

14° –20° angle

slight angle

Figure 3. Sensor angle adjustment

angle
reversed

shim with taper down shim with taper up

slight angle

20° transom angle3° transom angle

angle
too steep

slight angle

Cable Routing

CAUTION: Do not remove the connector to ease cable routing. If the
cable must be cut and spliced, use Airmar’s splash-proof Junction
Box No. 33-035 and follow the instructions provided. Removing the
waterproof connector or cutting the cable, except when using a
water-tight junction box, will void the sensor warranty.

Route the sensor cable over the transom, through a drain hole or
through a new hole drilled in the transom above the waterline.

1. If a hole must be drilled, choose a location well above the
waterline. Check for obstructions such as trim tabs, pumps or
wiring inside the hull. Mark the location with a pencil. Drill a hole
through the transom using 20mm or 13/16" bit to accommodate
the connector.

2. Route the cable over or through the transom.

3. On the outside of the hull secure the cable against the transom
using the cable clamps. Position a cable clamp 50mm (2")
above the bracket and mark the mounting hole with a pencil
(see Figure 4).

4. Position the second cable clamp halfway between the first
clamp and the cable hole. Mark this mounting hole.

5. If a hole has been drilled in the transom, open the appropriate
slot in the cable cover. Position the cover over the cable where
it enters the hull. Mark the two screw holes.

6. At each of the marked locations, use a 3 mm or 1/8" bit to drill a
hole 10mm (3/8") deep.

7. Apply marine sealant to the space around the cable and the
threads of the four #6 x 1/2" self-tapping screws to prevent
water from seeping into the transom. If you have drilled a hole
through the transom, apply marine sealant to the space around
the cable leading through the transom.

8. Position the two cable clamps and fasten them in place. If used,
push the cable cover over the cable and screw it in place.

9. Route the cable to the instrument being careful not to tear the
cable jacket when passing it through the bulkhead(s) and other
parts of the boat. To reduce electrical interference, separate the
sensor cable from other electrical wiring and “noise” sources.
Coil any excess cable and secure it in place using zip-ties to
prevent damage.

10.Refer to your echosounder owner’s manual to connect the
sensor to the instrument.

Checking for Leaks

When the boat is placed in the water, immediately check for
leaks around the screws and any holes drilled in the hull. Note
that very small leaks may not be readily observed. Do not leave
the boat in the water unchecked for more than three hours.

Testing on the Water

1. Become familiar with your echosounder’s performance at a
speed of 4kn (5MPH).

2. Gradually increase the boat speed and observe the gradual
decline in performance due to turbulent water flowing over the
transducer’s active surface.

3. If the decline in performance is sudden (not gradual), identify
the boat speed at which the onset occurred. Return the boat to
this speed, then gradually increase speed while making
moderate turns in both directions.

4. If the performance improves while turning to the side on which
the sensor is installed, the transducer’s position probably needs
adjustment. It is probably in aerated water.

cable cover

cable clamp

50mm (2")

Hull projection:
3mm (1/8")

Figure 4. Hull projection and cable installation

To improve performance, try the following one at a time in the
order given.

a. Increase the sensor’s angle in the water. Review “Plastic

Shim.”

b. Move the sensor deeper into the water in increments of 3 mm

(1/8").

c. Move the sensor closer to the centerline of the boat.

Fill unused screw holes with marine sealant.

NOTE: High-speed operation [above 35kn (40MPH)] may
require less projection in the water to improve performance and
reduce the chance that water pressure will cause the bracket to
release.

5. Calibration—To match the speed shown on the display to the

actual speed of the boat, you may need to calibrate the
instrument. Refer to your instrument owner’s manual.

Antifouling Paint

Aquatic growth can accumulate rapidly on the sensor’s surface
reducing performance within weeks. Surfaces exposed to salt
water that do not interlock must be coated with antifouling paint.
Use water-based antifouling paint only. Never use ketone based
paint since ketones can attack many types of plastic. Reapply
paint every 6 months or at the beginning of each boating season.

Maintenance, Repair & Replacement

Cleaning

Aquatic growth can accumulate rapidly reducing the sensor’s
performance within weeks. Clean the assembly with a soft cloth
and mild household detergent. If fouling occurs, use a stiff brush
or putty knife to remove the growth being careful to avoid making
scratches on the transducer face. In severe cases, wet sand the
surface with fine grade wet/dry paper.

If the paddlewheel becomes fouled or inoperable, it can be
removed for cleaning. Gently push back one retaining arm and
slide the shaft out. After cleaning, reinsert the shaft by pushing
back on the retaining arm. Be sure the shaft ends are secure in
the retaining arm notches.

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Sensor Replacement & Parts

The information needed to order a replacement sensor is printed
on the cable tag. Do not remove this tag. When ordering, specify
the part number, date, and frequency in kHz. For convenient
reference, record this information on the top of page one.

Replace broken or worn parts immediately. The water-lubricated
paddlewheel bearings have a life of up to 5 years on low-speed
boats [less than 10kn (11MPH)] and 2 years on high-speed
vessels. Parts can be obtained from your marine dealer or
instrument manufacturer.

Part
Paddlewheel Kit 33-007
Bracket & Wedge Kit 20-185-1

Obtain parts from your instrument manufacturer or marine dealer.

Gemeco Tel: [phone]
(USA) Fax: [phone]

email: [e-mail]
Airmar EMEA Tel: [phone]
(Europe, Middle East, Africa) Fax: [phone]

email: [e-mail]

Part Number

®

AIRMAR

TECHNOLOGY CORPORATION

35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA

www.airmar.com

Copyright © 2001  2011 Airmar Technology Corp. All rights reserved.

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