I have moved my transducer and it still doesnt work when under way. I have a 24' cat and I moved it from sideways on one of the motor mounts (it was only good there when idling) to the center of the tunnel. I figgured it would work up until the boat started to fly around 40 but no it quits at any speed above idle. The instructions say no more than a 15 degree offset but the cat hulls have far more. I saw a thru-the-hull transducer - the kind that actually go physically thru the hull - for about $80 on the web - maybe this is the way to go? There are also 2 thru-hull transducers - the kind that shoot the signal thru the fiberglass - mounted at various places that obviously the previous owner tried and failed.

BOTTOM LINE - How can I get depth readings at speed in a cat with no level surfaces touching the water other than a 1" area?

Thannks, TJ

I have had 2 cats and both of them did not work when on plane! I dont think there is anything you can do,I think the steps on the hull make bubbles under the boat!

my 38 scarab only works at idle aswell,the signal needs to hit the bottom and bounce back,hence you have your reading,if your moving to fast,it wont work

If there isn't water touching the underside of the boat where the transducer is mounted, it isn't going to work.... the signal cannot transmit through air. Whatever type of transducer you install, bottom line has to be where your going to have water...

Jjones.... your depth should work at speed, I can be running 60mph and it works fine. If you get air under the transducer, it will stop working... example, step hulls.... something forward of transducer that is causing air bubbling under transducer... etc...

I had the same problem on my 27 daytona cat. I bought the pickup that you are talking about that went through the hull and still does not work past idle.