Installation Notes - Thru-Hull Transducer - Raymarine L470 Instruction Manual

Installation Notes – Thru-Hull Transducer
Detailed instructions for this installation will be included with the trans-
ducer. In this section, we will note just a few important points.
1. Earlier we listed three general rules for placing transducers. All of
these rules apply when you are mounting a thru-hull transducer.
Here are some other rules for selecting the best mounting location:
For planing hulls – Install in the flat planing area near the stern.
Always install forward of the propeller(s) and shaft(s).
For small displacement hulls – Install near the centerline of the hull
and 1/3 of the way forward from the stern. Always install forward of
the propeller(s) and shaft(s).
For large displacement hulls – Install near the centerline of the hull
and 1/3 of the way aft from the bow. Always install forward of the
propeller(s) and shaft(s).
For sailboats – Install forward of the leading edge of the keel, to one
side and near the centerline of the hull.
2. Choose a location where you can easily reach the transducer from
inside the boat. This will allow you to service the unit. Allow at least
6" (152 mm) of headroom above the transducer.
3. When choosing a mounting location, drill a small pilot hole (1/8" or 3.2
mm) from the inside of the hull. Before you drill the hole, be sure you
will be able to reach the large nut on the top of the unit, and that there
will be enough clearance for the cable. If there is a strake or other
feature on the hull, drill from the outside of the hull instead. (This
small hole can be filled easily if the mounting location is not suitable.)
4. The position of the transducer is especially critical on high speed
boats (capable of more than 20 knots). Check the locations of the
transducers on similar boats before installing the transducer in your
own boat. Choose the location which will offer the best performance.
5. If the bottom of the hull at the mounting location is flat, you can mount
the transducer directly through the hull. If the hull rises at an angle
(the "deadrise angle") of more than 10°, you must include a mounting
block or "fairing." The transducer must be mounted in a vertical
position. Attach the fairing block to the hull as firmly as possible. This
fairing block must be able to resist the drag of the water against the
hull, and must also be completely waterproof.
Installation
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