Installation
Assembling
1. Insert the multisensor’s pivot posts into the recesses on the
sides of the bracket (see Figure 3).
2. Press the two nuts into the slots in the back of the bracket.
3. Align the holes in the multisensor, bracket, and nuts. Insert the
two machine screws capturing the nuts. Tighten the machine
screws until the multisensor will stay in the “up” (released)
position unaided.
Marking & Hole Drilling
1. At the selected location, position the multisensor, so it projects
3mm (1/8") below the bottom edge of the transom (see Figure 4).
2.
Being sure the bottom of the multisensor is parallel to the
waterline
, mark the location of the screw holes with an “X” in the
center of the two outer most slots.
Warning
: Always wear safety goggles and a dust mask.
3. Using a 4mm, #23, or 9/64" drill bit, drill two holes 22mm (7/8")
deep at the locations indicated. To prevent drilling too deeply,
wrap masking tape around the bit 22mm (7/8") from the point.
Fiberglass hull
—Minimize surface cracking by running the drill
in reverse until the gelcoat is penetrated.
Plastic Shims
•
Standard transom
(13° transom angle)—The bracket is
designed for a standard 13° transom angle. The 9° shim is
not
needed for this installation. If your boat is capable of speeds
above 20kn (28MPH), install the bracket with the 4.5° shim,
taper
down
(see Figure 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° shim with the taper
down
. If your boat is capable of speeds
above 20kn (28MPH), install the bracket with both the 9° and
4.5° shims, taper
down
(see Figure 5). This ensures that the
paddlewheel will be in contact with the water at high speeds.
Install the 4.5° shim against the transom after shaving the
interfering portion of the rails and lower bump. Place the 9°
shim and bracket assembly on top.
• S
mall aluminum and fiberglass boats
(20° transom angle)—
Use the 9° shim with the taper
up
. If your boat is capable of
speeds above 20kn (28MPH), install the bracket with only the
4.5° shim, taper
up
.
•
If you are unsure about using the shim(s)
, do one of below:
• Measure the transom angle of your boat using a digital level
or bubble level and protractor. Then follow the instructions for
your transom angle.
• Experiment with the shims by following the instructions
“Mounting & Adjusting”.
2
Figure 3. Assembling
pivot post (2)
recess (2)
bracket
nuts
machine
screw (2)
slot (2)
Mounting & Adjusting
1. Apply marine sealant to the threads of
two, #10 x 1-1/4", self-tapping bracket
screws to prevent water seepage into
the transom.
Be sure
the nuts are in the
slots in the back of the bracket and any
shim(s) is in place (see Figure 3).
Screw the multisensor to the hull (see
Figure 4).
Do not tighten the screws
completely at this time.
Caution
: Do not position the bow of
the multisensor lower than the stern
because aeration will occur.
2. Using a straight edge, sight the
underside of the multisensor relative to
the underside of the hull (see Figure 5).
The stern of the multisensor should be 1–6mm (1/16 –1/4")
below the bow of the multisensor.
Caution:
Do not position the multisensor farther into the water
than necessary to avoid increasing drag, spray, and water noise
and reducing boat speed.
3. Using the vertical adjustment space in the bracket slots, slide
the multisensor up or down until the bottom left corner of the
multisensor projections 0–3mm (0–1/8") below the bottom of
the hull (see Figure 4). When you are satisfied with the position
of the multisensor, tighten the two bracket screws.
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
multisensor’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.
AIRMAR
®
Figure 4. Vertical adjustment and cable routing
50mm (2")
cable cover
Hull projection
0–3mm (0–1/8")
parallel to
cable clamp
waterline
AIRMAR
®
