Thru-hull transducers are mounted through a hole drilled in the bottom of the
boat and protrude directly into the water. This type of transducer generally
provides the best performance.
Thru-hulls are recommended for displacement hulls and boats with
straight-shaft inboard engines. You’ll also need a fairing block that allows the
transducer to be mounted properly. Thru-hull transducers must be installed with
a fairing to ensure proper alignment and a secure fit.
Thru-hull transducers must be positioned in front of the propeller, rudder,
keel or anything else that may create turbulence. They must be mounted in a
position that is always underwater and angled straight down.