Depth sounder woes

[Joe Myerson]

Last season, the alarm on my ancient (original equipment?) Signet depth sounder started screaming constantly, but the sounder was working. I ignored the problem, expecting to remove the cockpit unit and ship it to Signet (they still exist) during the off-season.

Life, and later Covid-19, intervened.

My boat was finally launched this week. The yard warned me that my sounder was "shot." Not only was it screaming constantly, but the readings were "all over the place."

I assumed that I could use the sounder when needed, turning it off when the screaming became intolerable. But I was wrong: The readings were jumping around like mad as I tried to thread my way towards my anchorage in an unmarked channel that had shifted over the winter.

So, I ended up hard aground.

Here are my questions:

1) If the alarm is going off, can I assume that the fault is in the cockpit unit?

2) If so, I just happen to have a replacement unit, courtesy of Bruce and Cathy, who replaced Realization's Signet instruments some time ago. Will swapping out the older unit for the second-hand one solve the problem?

3) If it's the transducer, how should I proceed? Should I get a new unit that hopefully will fit into the existing round hole? If so, which unit?

CAVEAT: I am perhaps the most inept marine electrician on the planet. A friend used to do my wiring, but he vanished after his boat burned to the waterline a few years ago. (No, not from bad wiring. He left a heater going in the boat while he went for lunch.)

Thanks for any input.

--Joe

[Joe Myerson]

Update: I checked the existing depth sounder and it is the very same model. So few wires, I think I can handle it. Of course, if it doesn't work then, it will be a transponder problem.

[kerrydeare]

Update: I checked the existing depth sounder and it is the very same model ... I think I can handle it ... if it doesn't work then, it will be a transponder problem.

Probably not worth a haul right now depending on your sailing plans. These days most charting apps (or whatever your choice) will get you through the season, and of course I suspect you know your area well enough. I'd say wait until you haul in the fall and then go from there. Maybe save you time and effort (and $).

[Joe Myerson]

Kerry,
I installed Cathy's Signet sounder, and got a mysterious (not in manual) error message, so I called Signet Marine in CA. They explained that Cathy's boat has a different transducer than mine. I'm going to mail both sounders to them, and they'll repair at least one of them. Meanwhile, I will just rely on my eyes and memory. No sense on giving up sailing for this. After all, as my dermatologist said when I told her I would NOT give up sailing, despite a few pre-cancerous spots, "well, there's no better way to social distance."

Fair winds,

--Joe

[Frenchy]

Hi ya Joe, I can empathize- same depth sounder, same degree of dissatisfaction. On my unit, it
seems that if the transducer face is whistle-clean, it works okay. After a few weeks in the water, though,
the depth numbers go awry. For example, in about 7 feet, it reads 1.7. I never know exactly how deep
it is.
My old boat had a hummingbird glued inside the hull and that actually was better. The bad thing was
that the readings would go blank at any odd time- usually when you needed them. Maybe the transducer
lacked the power to go through the fiberglass reliably- I don't know.
I think my next lay-up project will be to move the Signet transducer inside the hull- maybe that'll
work better. - Jean

[Steve Laume]

I removed the old transducer and mounting block when some part of the system failed.

I installed one of those cheap little Humming Birds, with the transducer glued inside the hull and it has worked flawlessly. I see no point in having another hole in the boat, for a depth sounder, these days.

Time to break out the lead line, Steve,

[Steve Darwin]

A timely topic here, since Arabella's old Combi depth sounder (International Marine) stopped working yesterday - when we needed it, of course. The speedometer part of the thing hadn't worked in years. I could get down and start testing circuits, but this is old, clunky, late 70's early 80's technology, and the thing occupies a large hole in the cockpit bulkhead. So I'm looking to replace it and would welcome recommendations.

I'll need to fill or cover and re-drill the existing bulkhead hole. Thinking of a piece of teak. Or plastic? What adhesive would be best to make it watertight?

A transducer that affixes to the inside of the hull would be easiest to install and no need to haul the boat. Perhaps the old Combi"s existing thru-hull transducer could be used? Probably not a good idea.

Not wishing to spend a lot of $, but looking for reliability, of course. Steve Laume: What Humminbird model do you have and like?

Thanks for comments and help. -- Steve Darwin

[tjr818]

. . . I'll need to fill or cover and re-drill the existing bulkhead hole. Thinking of a piece of teak. Or plastic? What adhesive would be best to make it watertight? . . . .

Check the March/April issue of Good Old Boat. There is an article there called Hole In One. The guy took the insides out of his old gauge and mounted the new gage in the frame of the old gage. No holes to drill or fill. It won't work for everyone, but it would have worked for me.

[Steve Laume]

I don't remember the model of the Humming Bird depth sounder I bought. It was right around $100. It reads to 600', has alarms for shallow water, can be set for transducer height differential and will shoot through the hull. It does not interface with other instruments and I prefer it that way. What more could you want in a depth sounder? I did have a problem at one time where the alarm was going off. I was in a sleep deprived state and didn't want to deal with going through the manual to figure out what was going on so I cut the alarm wires thinking I could splice them back together at a more convenient time. That time has not yet arrived. Other than that it has worked flawlessly and seems to be a great bargain in the boating world.

I still remember the old units with the swirling light ring. We have come a long way, Steve.