Humminbird FF/ Transducer Question

[RustyGoat]

Last time I had the boat out my fish finder (HB 570) went nuts and the depth reading was all over the place. I was in 4-6' of water and it kept bouncing from .6' to 150'. A quick google search indicated the transducer was probably bad. Ordered a new one and just finished installing it. It's reading consistent and not bouncing around but is showing 7' with the boat on the trailer and the transducer 2' off the ground. Is this just because it's not in the water? I could have sworn the old one read correctly out of the water but I could be mistaken. Won't have a chance to get the boat in the water until at least Saturday.

 

[TNtroller]

As a general rule, a TD needs water to operate correctly, see if you can put it in a small or large size tub of water and etermine if readings are accurate or at least stable.

 

[grossman]

Yes that's normal. Transducer needs to be in the water to operate correctly.