Navman THROUGH HULL AND IN-HULL Installation Manual - page 6
6
Through hull & In-hull transducer installation manual
NAVMAN
2-2 Installing a through hull transducer
1 Select a suitable position for the
transducer (see section 2-1).
If the hull panel is too thin or the panel
might not be strong enough, consider
fi tting a reinforcing pad on the inside of
the hull.
2 Find the hole size required for the
transducer from the table above. Drill or
cut the hole in the hull. The hole must be
perpendicular to the hull surface.
3 For an insertable transducer:
i remove the locking nut or pin
rom the fi tting
ii pull the transducer out from the
hull fi tting
iii unscrew the nut from the hull fi tting.
For
a
fi xed transducer:
i unscrew the nut from the hull fi tting
ii hold the nut just inside the hole
in the hull
iii feed most of the transducer cable
through the hole in the hull (from the
outside) and through the nut.
4 Apply a thick layer of fl exible bedding
compound (such as Sikafl ex) to the
2-1 Positioning a through hull transducer
This transducer will be fi tted in a hole drilled
in the bottom of the boat. Select a position
for the transducer that has a smooth fl ow of
clear water over the transducer surface at all
times. This means that the transducer should
be ahead of any keel, hull projections, hull
openings, paddle wheel transducers, propellers
or propeller wash. If the bottom of the boat is
painted and the boat has been used, do not
mount the transducer where the paint is eroded
(an indication of turbulence).
In addition, position the transducer:
as close to the middle line of the hull as
possible and as deep as possible
where the deadrise angle is small
with suffi cient space inside the hull for
access and wiring
so that it will not interfere with launching
or retrieving the boat
Ideally a depth transducer should be fi tted so
that its axis is vertical, however it can be up to
15° off vertical.
Planing or displacement boat
Sailing boat
Suitable
locations for
transducer
Remove
transducer
Insertable transducer
Fixed transducer
Remove locking
nut or pin
Up to 15°