Stowe depth sounder intermittent!

[Wardy]

The stowe depth sounder on my boat works most of the time, but when i really need it, like going slow in shallow water entering a marina, it starts flashing at me. according to the booklet it means the transponder isn't working, or some such. Occasionally it registers '0m' on switch on and won't register until i have some reasonable forward speed.
I've checked all the connections to the transponder, through the central dataline and into the display; everything seems okay.
Any ideas you nice people?

 

[robbieg]

I had something similar with my Stowe unit-then got the boat scrubbed and all back to normal. You sure the tranducer isn't fouled-this could be the cause of your problems.

 

[Wardy]

I'll pull the sender out when i get back to the boat on thursday and give it a bit of a scrub, see what happens. Hopefully it will work after that
Cheers

Steve

 

[pragmatist]

Hi Wardy

We had this quite a lot - although not with a Stowe - Plastimo thru-hull. Have you tried adjusting the gain ? A change of bottom type (we found it particularly bad when we went to the Solent where the bottom type changes more than on the E Coast) can cause it - also if there's lots of stirred up mud which might be what you're talking about in a marina entrance on the E Coast.

We found fiddling about with the adjustment helped most of the time although in the Solent we resorted to turning it off when it wasn't shallow - to stop small daughter having 15 fits every time it squeaked !

 

[boatmike]

All very sensible advice but recognise that there is also a phenomena which I had explained to me once by a sonar expert but am not clever enough to pass on in detail which means that many sonars will have a shallow limit and will be overwelmed by the strength of the returning signal in very shallow water. Thats why you have to turn the gain down when shallow as the other poster said. It will of course limit the maximum depth it will record at but hey! after about 30 metres I lose interest anyway!

 

[andy_wilson]

Mine used to do that everytime I passed the Ferry in Lymington River. A combination of aeration of the water, and a muddy bottom I believe.

 

[rudolph_hart]

Bought a boat last year with Stowe, and it has exactly the same characteristics. It starts to flash below 3.5 meters (just when you need it!)

Forked out for a new transducer from AW marine (about £80 + Vear And Tear) which seems better quality than the original 10-year-old. I'll let you know if it cures it (launch 26th)

I fitted a whole new set of Silva instruments to my last boat, and, apart from the predictable 'berserker' when passing through a ship's wake in/outside Harry Jarber, the Depth never gave this sort of problem.

I shall be less than gruntled if the new trx doesn't cure the problem with the Stowe/Robertson Depth.

 

[rudolph_hart]

Referring to my last post: Can report that new transducer has totally cured the problem. Am completely gruntled.