Raymarine ST 40 Depthsounder problem

[JuanCH]

Hi all, here's my problem. I have installed in my 25 footer a ST 40 Raymarine depthsounder. When I am anchored in my marina the depthsounder reads ok (eg 2.7mts) but after twenty-thirty minutes it starts reading (2.2 - 2.3 -2.6) I checked the transducter but it seems ok. Can it be a kind of sreen saver since the boat doesnt move? or is it a technical problem? Thanks for the advice!

[Ex-Calif]

Originally Posted by JuanCH

Hi all, here's my problem. I have installed in my 25 footer a ST 40 Raymarine depthsounder. When I am anchored in my marina the depthsounder reads ok (eg 2.7mts) but after twenty-thirty minutes it starts reading (2.2 - 2.3 -2.6) I checked the transducter but it seems ok. Can it be a kind of sreen saver since the boat doesnt move? or is it a technical problem? Thanks for the advice!

Sometimes my ST60 does that. Sometimes underway it will read really low for a couple of minutes then revert to normal.

I chalk it up to freak electrons or debris in the water.

I have wondered if fish passing close by the hull transducer would tweak it. They must in some way and perhaps with internal damping 2.6-0-2.6 gets averaged to 2.2-2.3

So many thing to think about. So many gremlins <sigh>

[bazzer]

My st40 does the same, I put it down to mud on the berth, works fine in slightly deeper water and a different bottom.