humminbird 1198c

[V Matt]

I have a bran new unit I tried it out on the water and found out that when I am going 3mp my depth is correct but when I am going fast my depth is way off. Any one have any suggestions?

Mat

[rnvinc]

More than likely, your xducer is coming out of the water as your boat rises up on plane...

2 choices (if this is the case)...

*Lower xducer more down into the water...
*Add an additional Dual Beam xducer with the AS SIDB Y cable and get this cheaper xducer farther down into the water ..(or install the Dual Beam as a shoot thru hull if your boat is glass)...

Rickie

[SeaRay]

I agree that your transducer may be coming out of the water as you get on plane.

[V Matt]

my boat is not a bass boat its a crappie boat with a 40h merc, never had that problem
with my old depth finder I put the transducer at the same location.

Thank guys for your information

[rnvinc]

Post some pix of your transom xducer installation...

Both from the rear and each side with the camera at xducer level...

Rickie