Bought new ranger rt 188 problem is they mounted humminbirdtransducer behind trim tabs that are on bottom.
Sonar looses bottom contact what to do?
J D

Does it lose it at a certain speed, or just sitting in the boat? Are you on the front deck when it loses?

It may be mounted a little high, but that is usually a good thing for fishing timber. I think those trim tabs are just above the water when fully planed out.

Trim tabs are two small pieces of aluminum angle welded to bottom. They should have mounted it to transom I left or right . Works just trolling around its when you get at speed it loses bottom.
Was looking around found product called stern pad sticks to transom with some kind of 3m tape supposed to be strong. Didn't really want to put a lot of holes in new boat.
J D

Yes, the trim tabs just skirt the top of the water and create a 'bubble hole' when running. The mount for the 'ducer should have been more inboard.

I have 3 transducers on the back of my skeeter: side scan, down scan/2d, and one mounted in hull. The depth is set to read from the in hull, but even I lose bottom when I am on pad. If you want a better option, you can move it below the mounting plate for the motor.

Have the "they" install the transducer properly for that hull. No excuse for putting a transducer aft of the trim tabs--this is just ignorant.

You may want to add a transducer mounting board so you can try different locations without drilling more holes in your transom.

that's normal when getting speed. the transducer breaks the water so it doesn't get full contact. I know with garmin you can get a Y cable that goes to a thru-hull transducer and will read depth when the other one loses contact. I'd imagine humminbird wound have the same thing.

Any external mounted transducer will lose bottom contact when you get on plane. You have to go thru hull to have it read while on plane

Thanks for info

Not true. My center console will read all the way to 48 mph which is as fast as it will go. Not all boats are able to use a shoot thru hull. The shoot thru are mainly for bass boats and high performance boats that the fiberglass is thin enough for the transducer to shoot thru. Many center console boats have to have a thru hull or a transom mount like mine does.

Go over to BassBoat Central - bbcboards.net - - Humminbird Sonar/Gps. They have lots of photos for the Ranger RT 188. They are reading up to 50 mil. per hour. I have a 2013 that will read up to 40.

Mine is transom mounted and doesn't lose bottom contact until around 55mph, sometimes more.

Bought a mounting plate gonna redo it .