Jon boat depth finder

[Texas Slam]

Does anyone know of a depth finder that will operate GOOD on a jon boat ? I'm buying a john boat soon and have had problems in the past getting a depth finder that will work at any speed higher than an idle. I need something I can use while running at normal speeds......at least at more than an idle. I have heard that the almuminum hull creates too many bubbles........but surely their is something that will work.

[dogboy]

There is nothing that will work. My buddy bought a new flat bottom and rigged it out, he was told to shoot through the hull and that would work. He paid 100.00 for the transducer and it still wouldn't work. The hull creates air bubbles that passes under the transducer and that 's what causes the problems.

[longboat]

Plenty of depthfinders work plenty good on jon boats (been using them for years). The trick is to use a transom-mounted transducer and to be very careful when mounting it. The bottom of the transducer should be about 1/16-inch below the bottom of the boat, and should be mounted about midway between the side of the boat and the engine, and should be mounted midway between the longitudinal structural ribs that most jon boats have on their bottom. The trick is to get the smoothest flow of water under the boat for the transducer to read through.

You can mount a thru-hull or shoot-thru-the-hull on a jon boat, but they are much more difficult and need to be done very carefully. For example, a shoot-thru-the-hull transducer needs to have a perfect mix of bubble-free epoxy and/or grease between the transducer and the aluminum, needs a solid (single-hull) connection between transducer and water, and signal will be degraded quite a bit shooting thru the aluminum, but it is doable, IF you know what you are doing (I'm not sure that I'd even try it...).

[Whitebassfisher]

Mine works pretty well up to 20 mph or more. I have noticed that as I get going faster, it still tells me the depth, but is not able to draw a pretty chart. My boat is welded, which may reduce some bubbles since I don't have rivets. Mounting depth seems to be extremely critical though. Rather than drill holes through my transom, I mounted the transducer to a 1/4" X 2" aluminum flat bar. I them c-clamp the flat bar to the transom. That way, tiny changes can be made in how you set it, but even more important for me any way is that I can remove the transducer to keep from tearing it up while launching using the boat cart at the old lock & dam near Crockett.

[sqwaby]

Its all about the turbulence under the hull, I've installed electronics for over 20 years and on my own al boat(which I tried several things), best speed I can get is about 16-18 mph before the signal degrades. Not every Al boat is going to be the same, semi vees do a little better.

[propdinger]

I have a Boatright 2072 and have no issues with my Lowrance unit. The transducer is mounted on the rear; works great at speed and at rest. Hull thru transducers will not work on aluminum.

[longboat]

Hull thru transducers will not work on aluminum.

Tell that to Vexilar :þ