Autohelm Depth Sounder reading zero in deep

[Malcolm Crow]

Over the past year my 1995 Hunter 336 Autohelm ST50 Plus Depth Sounder has on occasion read Zero in deep waters. Not a big concern, but the last trip out it displayed eratic readings in 18' of water ranging from Zero to 18'. Has anyone had similar experience to know if this is just the start of it getting worse, or not to worry about it?

 

[Tom Payne]

Call Ray Marine Customer Service

800-539-5539

 

[Dick Carey]

ST50 Eratic (?) Reading

Malcolm,I too have an Autohelm ST-50 and the about a week ago in the middle of Mt. Hope Bay MA/RI, I also had strange readings for a few minutes. In water beleived to be 18-20 Ft (by chart)I suddenly noticed 0.1 Ft. then 'Zero' then a few Ft, then O.1 Ft, and then increasing slowly to 18-20 Ft range as expected.I certainly startled me and made me move to known even deeper water. I has been working fine since then.I dont know if something very big was swimming under me then (not likely in Mt. Hope Bay), or if it was electrical signal error. Still don't know what it all was.Dick CareyS/V Puffin

 

[Gene Roberts]

Bad Transducer

My depth meter on my 1995 H35.5 did the same thing most of last year. After having the boat hauled out for the winter I removed the depth read-out instrument and took it to a Raython dealer to have it benched checked. It checked o.k. using their transducer so the only conclusion was my transducer was bad. I bought a replacement from the Raython dealer the came the surprise. Removing the old transducer was one of the meanest jobs I have ever had to do on a boat! The transducer is located forward, under the V-berth with no room to get any kind of wrench on it. Even if I could have gotten a wrench on ot there is no way you have enough room for leverage. Remember, it is installed at the factory with 5200. I finally had to use a dremal too with a cut off wheel and cut the nut off. After that I was able to get a pipe wrench on the transducer shaft and after much work I slowly unscrewed the transducer out the bottom of the hull.The old transducer was bad as suspected, the new one works fine. Good luck!