[NogginDoc]

So, my depth finder still doesn't work after it was replaced by the maintenance shop where I bought the boat.

They removed the original Lowrance depth finder gauge and transducer (which was demolished after the boat was loaded on its trailer where the bunks were too long and extended too far behind the hull of the boat). They replaced it with a Hummingbird depth finder which apparently had the same dimensions to fit in the factory opening for the gauge. However, they sealed up the old holes where the original factory transducer was located, and installed the new transducer closer to the outdrive (about half the distance from the factory location towards the outdrive). I'm not sure if this make a difference from any cavitation, etc., or if it's too close to the outdrive.

At any rate, it doesn't work while the motor is on. It only reads the depth when the engine is off and when it's floating still in calm water. As soon as the engine is turned on, the depth readings are off the scale showing 500+ feet depths (my lake is lucky to get 50ft deep).

Anyone know where the best place to locate the transducer? Should I have a hull mounted "puck" transducer installed? I really need to have this depth finder working because my lake has several areas where there's shoals and boulders under the water which are not marked very well by any buoys.

Thanks.

[mikeyt]

Transom mount transducers can be affected by turbulence generated by the boat's hull so have to be carefully placed at the correct height to work properly. Even then, it wont always work perfectly. Check to see if the transducer is 'locked down' into position. If it isn't it will flop around at any sort of motion & give wild depth readings.

If you are considering an in-hull transducer you will likely have better results but....let a pro install it.