Clipper depth random readings

[PaulGS]

The depth guage on my new-to-me boat keeps playing up. It operates normally for a while then just gives random readings. The manual suggests this could be interference from e.g. the alternator - but I assume the previous owner didn't have this problem and not sort it. My next (first) step will be to look at the connections behind the display (the transducer is through hull and bone dry). Any thoughts?

 

[Refueler]

First thing I would check is the plug connection ... the plug and cable socket used are 'non marine' and subject to corrosion ...... I have had similar with Clipper and Echopilot ... unplugged ..... cleaned up and then repeatedly plugged / unplugged to get connection working well. I would not tape it together as I prefer such to 'breathe.
Periodic unplugging / plugging can keep it nice.

If you had said its In Hull in a tube .. then I would suspect air bubbles in the fluid ... but you say its through hull. The only way then is if the location is subject to turbulence when keel / other causes break up of water when sounder is working.

But you say ? "the transducer is though hull and bone dry" ????

If you actually mean that sounder is inside a tube and sounding signal is 'through hull' and the tube is dry - then that is wrong. The tube should have a fluid in to provide full signal path to hull ... the transducer should not actually touch inside hull but be just slightly up and the fluid ... cooking oil / castor oil / anti-freeze / water ... whatever you use.

 

[PaulGS]

First thing I would check is the plug connection ... the plug and cable socket used are 'non marine' and subject to corrosion ...... I have had similar with Clipper and Echopilot ... unplugged ..... cleaned up and then repeatedly plugged / unplugged to get connection working well. I would not tape it together as I prefer such to 'breathe.
Periodic unplugging / plugging can keep it nice.

If you had said its In Hull in a tube .. then I would suspect air bubbles in the fluid ... but you say its through hull. The only way then is if the location is subject to turbulence when keel / other causes break up of water when sounder is working.

But you say ? "the transducer is though hull and bone dry" ????

If you actually mean that sounder is inside a tube and sounding signal is 'through hull' and the tube is dry - then that is wrong. The tube should have a fluid in to provide full signal path to hull ... the transducer should not actually touch inside hull but be just slightly up and the fluid ... cooking oil / castor oil / anti-freeze / water ... whatever you use.

Thanks for responding Refueler. When you say 'plug connection' is that behind the unit (hidden in my boat behind lining)? What I call the transducer is visible as a £2 coin-sized black disc in front of the keel. It doesn't sound as if oil is going to be involved in my set-up - internally in the bilge the fitting and wires from it are dry.

 

[pmagowan]

Post a photo. There is a terminology problem. There are 2 main types of transducer, one that is in a through-hull fitting (ie there is a hole in the bottom of the boat in which the transducer is inserted like a 'plug') and one that is inside the boat, no hole and is pinging its signal 'through the hull'. The former is interfered with by air bubbles in the water, or being too close to the keel, or being too high up the hull such that the boats roll causes it to point in a direction where the sea floor is not within the 'cone'of its sensor. The later can be affected by the same things and also a poor contact with the hull. In general the layup from outside to inside the boat should go sea water, solid hull, interface fluid, transducer. If instead it is sea water, solid hull, air gap, transducer, there will be problems. Some hulls have a core that is not particularly good for reading through.

Of course problems may also be with any part or connection after the transducer also. Clean and remake all connections well.

Many transducers will not read accurately if you are going too fast. Since they are mostly of use when anchoring I would not presume that the previous owner had it working optimally.

 

[wombat88]

Make sure the transducer cable does not run too close to the the cable for the speedo.

(well it worked for me)

 

[scottie]

perhaps a orca checking the rudder

 

[neil_s]

I had a NASA depth on a previous boat. Although it gave a stable reading in water more than about 3 metres, in shallower water, it did suffer from random spurious readings. I put this down to re-reflection problems but never managed to cure it. I got quite good at filtering out the 'randoms' and picking out the 'reals'. The transducer was mounted inside the hull and I did consider fitting it through the GRP but never got around to it. I managed to live with it as it was!

 

[Plum]

The depth guage on my new-to-me boat keeps playing up. It operates normally for a while then just gives random readings. The manual suggests this could be interference from e.g. the alternator - but I assume the previous owner didn't have this problem and not sort it. My next (first) step will be to look at the connections behind the display (the transducer is though hull and bone dry). Any thoughts?

If all the previous advice does not solve the problem then maybe you have the problem I had when I fitted a new Clipper Depth. I was getting what appeared to be random readings but they were mostly rapid changes giving "multiples" readings of the actual depth. In most cases, if I watched closely at the rapidly changing display, the lowest reading I observed was the true depth. I solved the problem. In the instructions this problem is mentiond and gives you three different settings you can adjust: (1) gain delay (sensitivity threshold), (2)display update rate, (3) setting a slower averaging rate. The instructions explain what the 3 settings do and how to change them.

www.solocoastalsailing.co.uk

 

[Refueler]

Thanks for responding Refueler. When you say 'plug connection' is that behind the unit (hidden in my boat behind lining)? What I call the transducer is visible as a £2 coin-sized black disc in front of the keel. It doesn't sound as if oil is going to be involved in my set-up - internally in the bilge the fitting and wires from it are dry.

Yes the plug and socket in the cable that allows you to route the cable. The plug and socket used are not marine grade.

OK - you have a transducer that is outside hull ....... then I suspect aerated water if plug is not problem.

Another talks about angle of sounder 'signal' .... that in fact is a myth as the cone angle is designed to overcome serious boat heel .... another mentions speed ... again a myth - as long as water cleanly flows across the transducer - you'd be amazed how fast it can work in ...

 

[PhillM]

They do flutter quite a bit. I dont have an inboard, so its not the engine. Shallow water, bubbles from waves all make it lose its ability to be accurate. However, as said above you get used to knowing what is real and what is not. There is a setting you can change but I havent because you lose the ability to get any reading in less then x m of depth. As im in a shallow bilge keeler I do like to play in shallow water but even then I like to know how shallow it is.

 

[Plum]

They do flutter quite a bit. I dont have an inboard, so its not the engine. Shallow water, bubbles from waves all make it lose its ability to be accurate. However, as said above you get used to knowing what is real and what is not. There is a setting you can change but I havent because you lose the ability to get any reading in less then x m of depth. As im in a shallow bilge keeler I do like to play in shallow water but even then I like to know how shallow it is.

as I mentioned earlier, I have changed the settings and solved the wildly fluctuating readings but this has not affected shallow water readings. I am on the East Coast and most of the water is very shallow here.

www.solocoastalsailing.co.uk

 

[alancollins]

My NASA sounder works well until I cross the wake of another vessel, when it goes haywire. It then takes several minutes to settle down before recording accurately again. It is mounted in-hull. Are there any settings I can change that will prevent this without affecting its general performance?