Airmar P23 User Manual

INSTALLATION INSTRUCTIONSOWNER’S GUIDE &

Transom-Mount with Integral Release Bracket

Transducer or TRIDUCER® Multisensor

Models: P23, P32

WARNING: Always wear safety goggles and a dust
mask when installing to prevent personal injury.

WARNING: When the boat is placed in the water,
immediately check for leaks around the screws and
any other holes drilled in the hull.

17-122 rev. 07 04/071/11

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

CAUTION: Never strike the sensor with anything except
the palm of the hand. Never strike the paddlewheel.

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.

Applications

• Not recommended for boats with large inboard engine(s)

• Not recommended for stepped hull

• Good operation up to 55kn (63MPH)

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

• Adjusts to transom angles from 3

• Bracket protects sensor from frontal impact only

Tools & Materials

Safety goggles
Dust mask

Scissors
Masking tape

Electric drill
Drill bits:

Bracket holes 4mm, #23, or 9/64"

Transom hole (optional) 18mm, 11/16", or 3/4"

Cable clamp holes 3mm or 1/8"
Straight edge

Wire cutters (some installations)
Marine sealant (suitable for below waterline)

Screwdrivers
Pencil
Zip-ties

Water-based antifouling paint (mandatory in salt water)

° – 20°

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

Part No._________________Date___________Frequency________kHz

P32

P23

Pretest Temperature & Speed Functions

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

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 75mm (3") beyond the

swing radius of the propeller (see Figure 2). The starboard
side where the propeller blades are moving downward is
preferred.

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

NOTE: Starboard
side of hull where
propeller blades are
moving downward is
preferred.

75 mm (3")
minimum beyond
swing radius

Figure 1. Mounting location on single drive boat

Copyright © 1995 - 2011 Airmar Technol ogy Corp.

Figure 2. Template for starboard side of boat

centerline (keel)

drill here

Align this point with
bottom of transom

drill here

vertical

Installation

Assembling & Positioning

1. Insert the top of the sensor’s pivot posts into the slots on the top
back of the bracket. Rotate the bracket down until the bottom
snaps onto the sensor.

2. Cut out the template (see Figure 2).

3. At the selected location on the starboard side of the hull,
position the template so the arrow at the bottom is aligned with
the bottom edge of the transom (see Figure 3). Being sure the
template is parallel to the waterline, tape it in place.

Hole Drilling

Using a 4mm, #23, or 9/64" bit, drill two holes 22mm (7/8") deep
at the locations indicated. To prevent drilling too deeply, wrap
masking tape around the bit 22 mm (7/8") from the point.
Fiberglass hull—Minimize surface cracking by running the drill in
reverse until the gelcoat is penetrated.

Plastic Shims

parallel to waterline

Align template vertically

Align template arrow with
bottom edge of transom

Figure 3. Template position

AIRMAR

parallel to
waterline

AIRMAR

• Standard transom (13° transom angle)—The bracket is
designed for a standard 13° transom angle. The 9 degree shim
is not needed for this installation. If your boat is capable of

®

speeds above 35kn (40MPH), install the bracket with the 4.5
degree shim, taper down (see Figures 4 and 5). This ensures

that the paddlewheel will be in contact with the water at high
speeds.

• Stepped transom and jet boats (3° transom angle) —Use the
9 degree shim with the taper down (see Figures 4 and 5).

• Small aluminum and fiberglass boats (20° transom angle)—
Use the 9 degree shim with the taper up (see Figures 4 and 5).

• If you are unsure about using the shims—To determine if the
9 degree 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 (see Figures 4 and

5). The trailing edge of the sensor should be 1– 3mm (1/16–1/
8") below the leading edge of the sensor or parallel to the
bottom of the hull.

®

13° transom angle

20° transom angle3° transom angle

angle
reversed

slight angle

angle
too steep

slight angle

AIRMAR

®

thin shim

Figure 4. Plastic shims

thick shim

parallel

14° –17° angle

slight angle

Figure 5. Sensor angle adjustment

shim with taper down shim with taper up

2