SR-71

I'm curious if anyone with a stepped hull boat has had issues with their depth finder reading erroneously when up on plane? I own a 2004 38EC and find as long as I'm in the displacement mode my depth finder reads perfectly but when up on plane I get all sorts of odd depth readings. I suspect it's due to the stepped hull injecting air bubbles along the bottom when underway, and of course the transducer can not read accurately through air bubbles. The transducer in my Fountain 38EC is a "in-hull" type and mounted about half way point in the hull. Does anyone know of a good way to mount a transducer in a stepped hull boat to eliminate this problem?

Butch

Donzi1979

iTrader: (1)

I have the same issue with a twin step, and tried to mount forward of the first step without success on plane. The other issue is the coring in the hull. If you do a search it's been discussed before some have had luck mounting forward of the first step but most of what I have read you have to remove coring in some situations and I was not comfortable with that. I just use my Chart Plotter and hope it's reliable at speed.

Blueabyss

Butch is it factory installed? If not you should call the factory for recommendations. Never put on in that model boat but I have had the best luck mounting them as far back as possible and as close to center as possible. Before you mount it look under the bottom of the boat and make sure there are no through hull fittings that are causing turbulence in front of it. Might also look online to see if there is a diagram as to where the hull vents to and keep it away from that. We just put one on a 22 ft non stepped fishing boat and it reads fine until it gets into bigger waves. Boat is airing out. If the boat is coming out of the water you will loose depth for a few seconds.

Chris

SR-71

I am the 2nd owner of this 38EC so I'm not 100% sure the transducer was factory installed. And I'll need to take some measurements but I don't think it's mounted ahead of the first hull step. I'll need to look into this on my new install.

Another OSO member sent me this link below that shows an excellent underwater photo of the aeration of a stepped hull. If my transducer is mounted behind a hull step it's no wonder why I can't get a depth reading when on plane!

https://www.airmar.com/uploads/SpecA...ation-tips.pdf

Butch

ICDEDPPL

iTrader: (1)

You can get depth readings while underway?
That`s news to me. I never gave it a second thought, none of mine ever worked underway on any boat .

8Ballclan

We have a Donzi 33zx and use a P79 transducer mounted centerline and forward of the steps. It is a little farther forward than I would like but the location was all that was available in terms of easy accessibility.

We get depth at pretty much all speeds depending on water condition ... it does drop out at certain speed & water condition combos but overall it is a heck of a lot better than the original transom mount/peanut guage setup.

SR-71

8Ballclan - Thanks. Your reply gives me some encouragement that it might be possible to properly position a new transducer on my boat. What type of boat do you have?

Butch