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)
A
B
A
B
A
B
A
B
Figure 5. Distance between
corner of bracket and
bottom of transom
2
Figure 8. Bracket
retaining cover
Figure 6. Speed sensor or blank
closed
opened
screws
cover
speed
sensor
transducer
housing
bracket
screw
ac
tu
al
si
ze
ac
tual
si
ze
(self-tapping
#6 x 5/8")
self-tapping
screw
(some installations)
Copyright © 2003 Airmar Technology Corp.
Copyright © 2003 Airmar Technology Corp.
Copyright © 2003 Airmar Technology
Copyright © 2003 Airmar Technology Corp.
parallel to waterline
parallel to waterline
Figure 7. Cover
mounting ears
(some installations)
insert screw-
driver here to
remove cover
cover
tab in slot
flush with
housing
co
ve
r
ho
us
ing
Copyright © 2003 Airmar Technology Corp.