Pretest speed & temperature functions, Installation, Align arrow with bottom of transom – Airmar P66 User Manual

Page 2: Parallel to waterline, Hole drilling, Compensating for the transom angle: shim

38mm (1-1/2")

slope

of hull

Pretest Speed & Temperature Functions

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.

Installation

CAUTION: Install the bracket before attaching the sensor.

Hole Drilling

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

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

1. Cut out the template (see Figure 3).
2. 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 4). Being sure the template is parallel to the
waterline, tape it in place.

3. Using a 4mm, #23, or 9/64" bit, drill three holes 22mm (7/8") deep at

the marked locations.

Compensating for the Transom Angle: Shim

CAUTION: For boats capable of speeds above 20kn (28MPH)—The
trailing edge of the sensor must be deeper in the water than the leading
edge. This will ensure that the paddlewheel is in contact with the water at
high speeds.

For the best performance, the transducer beam must be aimed straight

at the bottom. Since the transom of most boats is angled, the bracket

must compensate for it. Measure the transom angle of the boat with an

angle finder.

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

standard 13° transom angle. The shim is NOT needed for this installation. Go to
"Mounting the Bracket."

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

taper down.

• Small aluminum and fiberglass boats (20° transom angle)—Use the shim

with the taper up.

• If you are unsure about using the shim—Experiment with the shim. Follow

the instructions: “Mounting the Bracket”, “Attaching the Senor to the Bracket”,
and “Checking the Angle and Projection.”

Figure 4. Template position

align template arrow with

bottom edge of transom

Align template vertically

slope of hull

waterline

Align arrow with bottom of transom

Figure 3. Template

for starboard side of boat

Drill at locations labeled “B”

for transom angles 16° through 22°

(most small aluminum boats)

Drill at locations labeled “A”

for transom angles 2° through 15°

(most boats)

B
A

Figure 5. Distance between

corner of bracket and

bottom of transom

Figure 8. Bracket

retaining cover

Figure 6. Speed sensor or blank

closed

opened

screws

cover

speed

sensor

transducer

housing

bracket

screw

tual

(self-tapping

#6 x 5/8")

self-tapping

screw

(some installations)

parallel to waterline

Figure 7. Cover

mounting ears

(some installations)

insert screw-

driver here to

remove cover

cover

tab in slot

flush with

housing

ing