Anti-fouling paint, Mounting location, Boat types – Airmar DST800 Retractable with Valve—TRIDUCER® Multisensor User Manual

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Anti-fouling Paint

Aquatic growth can accumulate

rapidly on the multisensor’s

surface reducing performance

within weeks. Surfaces exposed to

salt water must be coated with

anti-fouling paint. Use water-

based anti-fouling paint only.

Never use ketone-based paint,

since ketones can attack many

plastics possibly damaging the

multisensor.
It is easier to apply anti-fouling

paint before installation, but allow

sufficient drying time. Reapply

paint every 6 months or at the

beginning of each boating season.

Paint the following surfaces

(see Figure 1):
• Outside wall of the insert below

the lower O-ring

• Paddlewheel cavity
• Paddlewheel
• Exposed end of the insert
• Exterior flange of the housing
• Bore of the housing up 30mm

(1-1/4")

• Blanking plug below the lower O-ring including the exposed end

Mounting Location

CAUTION: Do not mount in line with or near water intake or

discharge openings, or behind strakes, fittings, or hull

irregularities that will disturb the water flow.
CAUTION: Do not mount the sensor where the boat may be

supported during trailering, launching, hauling, or storage to avoid

damaging the transducer’s face.

• The water flowing under the hull must be smooth with a minimum of

bubbles and turbulence (especially at high speeds).

• The multisensor must be continuously immersed in water.
• The transducer beam must be unobstructed by the keel or propeller

shaft(s).

• Choose a location away from interference caused by power and

radiation sources such as: the propeller(s) and shaft(s), other
machinery, other echosounders, and other cables. The lower the noise
level, the higher the echosounder gain setting that can be used.

• Choose a location with a minimum deadrise angle, so the transducer

beam will be aimed at the bottom.

• Choose an accessible spot inside the vessel with adequate headroom

for the height of the housing, tightening the nuts, and removing the
insert. Allow a minimum of 280mm (11").

Boat Types

(see Figure 2)

• Displacement hull powerboats—Locate amidships near the

centerline. The starboard side of the hull where the propeller blades are
moving downward is preferred.

• Planing hull powerboats—Mount well aft, on or near the centerline,

and well inboard of the first set of lifting strakes to insure that the
multisensor will be in contact with the water at high speeds. The
starboard side of the hull where the propeller blades are moving
downward is preferred.
Outboard and I/O—Mount just forward of the engine(s).
Inboard—Mount well ahead of the propeller(s) and shaft(s).
Stepped hull—Mount just ahead of the first step.
Boat capable of speeds above 25kn (29MPH)—Review the
installation location and operating results of similar boats before
proceeding.

• Fin keel sailboats—Mount on or near the centerline and forward of the

fin keel 300–600mm (1–2').

• Full keel sailboats—Locate amidships and away from the keel at the

point of minimum deadrise.

planing hulls

Figure 2.

full keel sailboats

large displacement hulls

small displacement hulls

fin keel sailboats

Best location for multisensor

stepped hull

outboard and I/O

Figure 1. Anti-fouling paint

outside wall

paddlewheel

bore of housing

exterior flange

O-ring

below lower

cavity

up 30mm (1-1/4")

of housing

insert

housing

exposed end

marine sealant on flange

Figure 3. Bedding and installing

cap nut

washer

hull

plastic housing

safety wire

housing

hull nut

insert

marine sealant on flange

stainless steel housing in metal hull

metal housing in non-metal hull

isolation

bushing

washer

and sidewall of housing

(plastic)

marine sealant on flange

cap nut

hull

safety wire

housing

insert

(plastic)

(metal)

hull nut

(P617V shown)

(SS617V shown)

and sidewall of housing

and isolation bushing where it contacts hull

BOW

►

(B617V shown)