Eagle Electronics SeaCharter 502cDF - Manual (Page 24)

16
Align transducer centerline with hull bottom. A dual frequency
transducer (left) and a single frequency transducer (right).
How low should you go?
For most situations, you should install your Skimmer transducer so
that its centerline is level with the bottom of the boat hull.
This will usually give you the best combination of smooth water flow
and protection from bangs and bumps.There, however, are times when
you may need to adjust the transducer slightly higher or lower. (The
slots in the mounting brackets allow you to loosen the screws and slide
the transducer up or down.) If you frequently lose bottom signal lock
while running at high speed, the transducer may be coming out of the
water as you cross waves or wakes. Move the transducer a little lower
to help prevent this.
If you cruise or fish around lots of structure and cover, your transducer
may be frequently kicking up from object strikes. If you wish, you may
move the transducer a little higher for more protection.
There are two extremes you should avoid. Never let the edge of the
mounting bracket extend below the bottom of the hull. Never let the
bottom – the face – of the transducer rise above the bottom of the hull.
Shoot-Thru-Hull vs. Transom Mounting
In a shoot-thru-hull installation, the transducer is bonded to the inside
of the hull with epoxy. The sonar "ping" signal passes through the hull
and into the water. This differs from a bolt-thru-hull installation (often
called "thru-hull"). In that case, a hole is cut in the hull and a specially
designed transducer is mounted through the hull with a threaded shaft
and nut. This puts the transducer in contact with the water.
Typically, shoot-thru-hull installations give excellent high speed opera-
tion and good to excellent depth capability. There is no possibility of
transducer damage from floating objects, as there is with a transom-
mounted transducer. A transducer mounted inside the hull can't be
knocked off when docking or loading on a trailer.
Transom
Transom
Hull bottom
Hull bottom
Transducer
centerline