Procedure for installing the thru-hull mount transducer
1.With the boat hauled out of the water, mark the location selected for mounting the transducer on the bottom of the hull.
2.If the hull is not level within 15° in any direction, fairing blocks made out of teak should be used between the transducer and hull, both inside and outside, to keep the transducer face parallel with the water line. Fabricate the fairing block as shown below and make the entire surface as smooth as possible to provide an undisturbed flow of water around the transducer. The fairing block should be smaller than the transducer itself to provide a channel to divert turbulent water around the sides of the transducer rather than over its face.
Hole for stuffing tube
Upper half
Lower half
BOW
Saw along slope of hull.
Figure 1-15 Construction of fairing block
3.Drill a hole just large enough to pass the threaded stuffing tube of the trans- ducer through the hull, making sure it is drilled vertically.
4.Apply a sufficient amount of high quality caulking compound to the top surface of the transducer, around the threads of the stuffing tube and inside the mount- ing hole (and fairing blocks if used) to ensure watertight mounting.
5.Mount the transducer and fairing blocks and tighten the locking nuts. Be sure that the transducer is properly oriented and its working face is parallel to the waterline.
Note: Do not