Humminbird 1158c Combo Installation And Operation Manual page 42

Deadrise Angle
• If the transom is behind the propeller(s), it may be impossible to find an area clear from
turbulence, and a different mounting technique or transducer type should be
considered, such as an Inside the Hull Transducer (see Inside the Hull Transducer
Installation).
• If you plan to trailer your boat, do not mount the transducer too close to trailer bunks or
rollers to avoid moving or damaging the transducer during loading and unloading of the boat.
• If high speed operation is critical, you may want to consider using an In-Hull transducer
instead of this Transom Mount transducer.
NOTE: The hydrodynamic shape of your transducer allows it to point straight down without deadrise
adjustment.
NOTE: If you cannot find a transom mount location that will work for your high-speed application, find
an In-Hull Transducer by contacting our Customer Resource Center at either 1-800-633-1468 or by
visiting our Web site at humminbird.com.
2. Preparing the Mounting Location
In this procedure, you will determine the mounting location and drill two mounting holes, using
the transducer mounting bracket as a guide.
1. Make sure that the boat is level on the trailer, both from port to starboard and from bow to
stern, by placing your level on the deck of the boat, first in one direction, then in the other.
2. Hold the mounting bracket against the transom of the boat in the location you have
selected. Align the bracket horizontally, using the level; make sure that the lower corner
of the bracket does not protrude past the bottom of the hull, and there is at least 1/4"
clearance between the bottom of the bracket and the bottom of the transom for
fiberglass boats, and 1/8" clearance for aluminum boats.
Transom Mount - DualBeam™ PLUS
• On boats with stepped hulls, it may be possible to
mount the transducer on the step. Do not mount
the transducer on the transom behind a step to
avoid popping the transducer out of the water at
higher speeds; the transducer must remain in the
water for the control head to maintain the sonar
signal.
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