Depth Finder & Sounder Working Intermittenly

[JRowenole]

Last Sunday was our first opportunity to really run fast our 2006 340 on the lake.

While navigating out of our marina at idle speed, my depth finder was working fine. However, when I throttled up to get the boat on plane, the depth finder started to show zero to three foot depth readings and the corresponding depth sounder alarm would go off (I don't think this was because of debris under the boat). This happened on and off for about 5 minutes then would subside, and then start again.

Any ideas?

Thanks so much.


John

 

[tdappleman]

You may be experiencing water turbulence from under the boat and/or from around the propeller area. What kind of transducer do you have installed?

 

[skolbe]

Are you referring to the Smartcraft Transducer? Mine occasionally will lose readings - you may have some build-up on the bottom. But - the transducer is flaky occasionally - I have seen others make similar comments.

 

[Lazy Daze]

You may be experiencing water turbulence from under the boat and/or from around the propeller area. What kind of transducer do you have installed?

Yes, do you have the standard depthfinder (thru-hull) from SR, or are you talking about an aftermarket sounder with a transom-mounted transducer?

 

[Scotto97]

I have the same problem with my Lowrance that was installed by Marinemax. The depth gauge will suddenly show around three feet and the shallow alarm will sound. This happens even in open water. Kinda freaks me out - would like advice on how to correct it.

The Smartcraft gauge doesn't seem to have this problem.

 

[Pseudomind]

What device is displaying this? Do you have more then one device which shows depth, eg. Raymarine A50D, RL80CRC, Rl70..etc?

Not sure I can be of any help, but this information may assist others in aiding you.

Last Sunday was our first opportunity to really run fast our 2006 340 on the lake.

While navigating out of our marina at idle speed, my depth finder was working fine. However, when I throttled up to get the boat on plane, the depth finder started to show zero to three foot depth readings and the corresponding depth sounder alarm would go off (I don't think this was because of debris under the boat). This happened on and off for about 5 minutes then would subside, and then start again.

Any ideas?

Thanks so much.


John

 

[Morpheus]

Same thing with my Smart Craft Tranducer from the factory. I asked MM about this and they said it's normal and is usually caused by a distrubance in the water.

 

[sbw1]

This can happen in cold water where the temperature line (thermocline) between the warm and cold water meet. I've had it going under the Mackinac bridge in 120 feet of water. It does get your attention. Debris in the water and bubbles can cause it too. You don't say were you boat so this is purely speculation.

 

[JRowenole]

The depth display is on the Smartcraft display that came with my new 2006 340.

I boat on a freshwater lake. Water temp reading on Sunday was 74F.

Never had this problem before. Only "problem" with this has been very temporary in nature, i.e., when getting close to the marina entrance/exit, possibly going over submerged debris, etc.

My alarm is set for 10 feet.

Average depth on this lake is in excess of 50 feet.

Thanks again.


John

 

[Morpheus]

10feet, that would be like heaven here in the Tampa Bay. I'm happy when I have 4-5 feet 10 I would never have to worry.

 

[Lazy Daze]

OK, so it's the thru-hull transducer. Maybe a Smartcraft systems reset could help - I forget off-hand how to do it, though. Something about pressing and holding the two outer buttons?

Other than that, could be a bad ducer, or a problem in the ECM programming. If it was me, and before I spent too much time, I would have a dealer hook-up a scan tool.

Unless, any chance you got something hung up on the hull bottom? You got 74* for your water temp? Take a dive down under with a rag. Look for anything obvious and clean off the ducer - maybe it's got some growth on it.

 

[JRowenole]

Thank you, Lazy Daze.

Morpheus - I know where you are coming from. I grew up on Tampa Bay (Beach Park Isles), and when I was a teen ran-a-ground a couple of 15 foot tri-hulls with 40 HP Johnson Outboards a few times back in the old days!!! (my step-father about murdered me!).


John

 

[sbw1]

I noticed we've got a fair amount of stuff floating in our lake now as a result of high winds for 3 or 4 days. I'm talking leaves and other organic debris that have yet to settle out. Soon it will be pollen. This stuff gets run over by boats and ends up several feet down before disappearing for good. It can cause false readings.

 

[everthing's irie]

My smart craft sounder does the same thing. Best I can tell is debris passes under the ducer and it gets a false reading. My ducer on my chartplotter/fishfinder does not give those same false readings. It is a shoot through hull.

I've had the same thing happen on other boats I've owned.

 

[elreyos]

I've had this same phenomenon happen to me in open water in 150ft + water. What I discovered was that it occurred when following my buddies at cruise. Mind you I'm talking about following at say 100yds from the guy ahead. We then experimented following each other and duplicated the problem. We decided it was caused by the noise of the lead boats screws. Probably fooling the sonar waves from the transducer. JR you say it occurrs on approach to the marina, mite be noise or feedback comming from the docks.

 

[sbw1]

I've had this same phenomenon happen to me in open water in 150ft + water. What I discovered was that it occurred when following my buddies at cruise. Mind you I'm talking about following at say 100yds from the guy ahead. We then experimented following each other and duplicated the problem. We decided it was caused by the noise of the lead boats screws. Probably fooling the sonar waves from the transducer. JR you say it occurrs on approach to the marina, mite be noise or feedback comming from the docks.

More than likely it is bubbles from the lead boat vs. the sound of the lead boat.

 

[JRowenole]

Thanks again everyone.

However, I am "used to" the occasional alarm when getting close to the marina entrance/exit structure, the occasional debis that is probably under the boat, etc.

This time, it was occuring much more frequently and in open water.

Everything's Irie - I see you also boat on Lake Allatoona. Have you noticed any difference lately with your depth alarm?

 

[chuck1]

My smart craft sounder does the same thing. Best I can tell is debris passes under the ducer and it gets a false reading. My ducer on my chartplotter/fishfinder does not give those same false readings. It is a shoot through hull.

I've had the same thing happen on other boats I've owned.

First time I ever really noticed it was this past weekend on Allatoona. I even commented about it to Judy that is must have to do with all the debris:thumbsup: Garmin keep reading fine the whole time.