Transducer reading problem on aluminium boat

[aveyron]

Hope this is not the subject of a previous post but I can't find one.

I can not get a proper reading even going very slow. I have a Tracker Pro Team 175 and am using a Humminbird 797c2. I have moved the transducer all over the back of the boat and the step to no avail. It is starting to look like a piece of swiss cheese. It only reads going at a crawl. Picking up a little speed, the transducer is still submerged but the're is no proper reading anymore.

I know they can shoot through aluminium (my friend has done it) but I am not sure how sensitive the transducer reading would be. I also don't fancy having to rip out the rear deck.

Is there a trick to mounting a transducer on an aluminium hull?

Thanks
Aveyron

[Shellback]

Number 1, stop drilling holes in the transom, and get a transducer mounting board. Number 2, I think your unit is side imaging, so that isn't going to work as a shoot thru hull. Are you paying attention to the hull bottom when you are mounting the transducer? Gotta be something that's causing turbulence at the transducer. How about the little rubber plug that pops in between the transducer body and the swivel mount? I understand the early units didn't come supplied with them, and even kits that did, people didn't know what to do with them. Can you get some pictures of your set up? That would help.

[aveyron]

Originally Posted by Shellback

Number 1, stopp drilling holes in the transom, and get a transducer mounting board. Number 2, I think your unit is side imaging, so that isn't going to work as a shoot thru hull. Are you paying attention to the hull bottom when you are mounting the transducer? Gotta be something that's causing turbulence at the transducer. How about the little rubber plug that pops in between the transducer body and the swivel mount? I understand the early units didn't come supplied with them, and even kits that did, people didn't know what to do with them. Can you get some pictures of your set up? That would help.

"Little rubber plug"? Oops, I wonder what I did with that. What does it do? What is a transducer mounting board?

A picture may not be of any use as I have now mounted the transducer on an arm which clamps on to the transom which I can adjust in height. I'll get a picture of the transom this week when I go fishing. Is it ok if the transducer is totally submerged when running or should it just be skimming (which is difficult to achieve)?

[Shellback]

Here's a picture of a W/C members boat. It shows the transducer mounting board, and also the correct height of the transducer. The curved piece is a spray shield. notice the transducer puck's outer edge is split mid way horizontally by the boat bottom. The inner edge lies deeper up into the hull.
http://www.walleyecentral.com/forums...pictureid=1879

Here's a link to Cabelas for the transducer mounting boards.
http://www.cabelas.com/product/Cabel...h-All+Products

[Shellback]

if you look at your transducer, there's a little gap between the puck and the mounting bracket. The rubber plug fills that gap and is supposed to reduce turbulence.

[aveyron]

Originally Posted by Shellback

Here's a picture of a W/C members boat. It shows the transducer mounting board, and also the correct height of the transducer. The curved piece is a spray shield. notice the transducer puck's outer edge is split mid way horizontally by the boat bottom. The inner edge lies deeper up into the hull.
http://www.walleyecentral.com/forums...pictureid=1879

Here's a link to Cabelas for the transducer mounting boards.
http://www.cabelas.com/product/Cabel...h-All+Products

Ah ha. Very interesting! What does the spray shield do? Does it just knock down the rooster tail or does it help with the transducer reading? This boat doesn't seem to have a step. Does it hurt if the transducer is partly submerged when running or should it only skim? Can you run your boat full speed and still get a reading like this?

I'm going to freeze my tail going out on the boat this week.

[h8go4s]

Transducer installation is covered in your owner's manual.

[Shellback]

Originally Posted by aveyron

Ah ha. Very interesting! What does the spray shield do? Does it just knock down the rooster tail or does it help with the transducer reading? This boat doesn't seem to have a step. Does it hurt if the transducer is partly submerged when running or should it only skim? Can you run your boat full speed and still get a reading like this?

I'm going to freeze my tail going out on the boat this week.

The shield is just for spray, and the transducer always has to run in clean water. I guess that means submerged completely. I get a reading at 30MPH, that's as fast as I can go!

[aveyron]

Originally Posted by h8go4s

Transducer installation is covered in your owner's manual.

I know, but their suggestions for aluminium boats don't work for me and a lot of other people.

[Jason Halfen]

I would be happy to provide some recommendations for mounting your compact Side Imaging transducer for your Humminbird 797.

One of the ideas from above is the place to start: I strongly recommend that people who do their own rigging start with a transducer mounting board on their transom. That will prevent you from punching even more holes in the transom, and allow you to make the fine adjustments that are necessary to obtain the best possible Side Images.

After that, you need to find a place on the transom where the delivery of water to the transducer is as smooth as possible. That means....no strakes, ribs, or rivets in front of the transducer that would disrupt the smooth flow of water to the transducer.

Typically, transducers are mounted right where the transom meets the waterline, with the back of the transducer tipped down a notch or two, tipping it a little further into the water than what it would be if it were parallel to the bottom of the hull.

Side Imaging transducers also require clean sightlines to the left and right of the transducer. That means....no blockage by the outboard or other transom mounted motors or accessories, livewell intakes, plugs, etc.

If you post pictures of your transom, and the bottom of the hull in front of the trandsucer mounting area, we'll be able to give you some more specific recommendations on where the compact Side Imaging transducer should be mounted.