Humminbird 1157C - Manual (Page 47)

• As a general rule, the faster the boat can travel, the further aft and closer to the centerline of the
hull the transducer has to be located in order to remain in contact with the water at high speeds.
2. Trial installation
You will not be able to adjust the mounting after an inside the hull transducer is installed. It is best,
therefore, to perform a trial installation first that includes running the boat at various speeds, in order to
determine the best mounting area before permanently mounting the transducer.
1. Plug the transducer into the control head, then power up the control head. When the control
head detects a functioning transducer, it will automatically enter Normal operating mode.
2. View the sonar signal at its best by holding the transducer over the side, immersed in the water,
so that it is pointing straight down over a known flat bottom. Use the display to benchmark
against the sonar signal that will be detected once the transducer is placed in the hull.
3. Place the transducer body face down at the identified mounting location inside the hull, with the
end that has the mounting knuckle pointed towards the bow of the boat.
Preferred Mounting Area
Areas of Possible Turbulence
Rivets Strakes
Transom Hull
Stepped Hull
Step Rib
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