Deck wash pick up interference

G’day all, looking for some opinions here....(running a HDS12 Gen2 and stock 83/200kHz tranny).

I’m collecting a lot of interference when underway even at low speeds and despite making several adjustments in transducer height it’s not getting better, in fact not changing at all.

My suspicion is that possibly my deck wash pickup (which is a flush hole in an Ali hull) is possibly creating a bubble trail... now before I relocate the transducer do does anyone think I might be out to lunch or is it a reasonable suspicion ....?..




scano's picture

Posts: 1154

Date Joined: 31/05/07

Almost definite

Tue, 2018-11-13 19:09

What you describe for the deck wash intake, would be causing some form of interference.

particularly because there will be a level of the water stream being caught on the lip of the water intake hole, then causing turbulence thereafter.

I reckon you are on the money in thinking the intake is causing you grief.  




Faulkner Family's picture

Posts: 15636

Date Joined: 11/03/08

 i had similar probs but mine

Tue, 2018-11-13 20:15

 i had similar probs but mine was water intake for a stern drive, moved the tranny and then was able to get real good reads. it may only need to go over an inch or 2 away from the motor 


RUSS and SANDY. A family that fishes together stays together

Posts: 563

Date Joined: 27/08/09

 Sounds probable...... but

Wed, 2018-11-14 12:05

 Sounds probable...... but test it.

Seal the pickup point with a cork, and cut it flush with the hull...... Go for a run and test it.

Or try running you deck wash and see it the problem resolves. I may be the venturi effect while the boat is in motion is pulling air back down the deck wash plumbing and leaving a bubble trail.

Posts: 2

Date Joined: 30/06/15

Thanks for the comments..I’ll

Wed, 2018-11-14 13:25

Thanks for the comments..I’ll post the results after the weekend