Transducer placment

[whistler]

Captnchris, I had to reread your post a couple of times and then think about it. I'm kind of slow and some of what you said goes against what the mfg tells us. So it took a while to digest! That's not to say you're not right as I've found out many mfgs will use any excuse for their product that is not performing as they say it will. They certainly are slow and/or not willing to admit fault or take blame in very many situations. It's usually their motive to try and convince the consumer it's their fault by improper mounting or operator error etc.......! I would like to see more pictures of your transducer mounting from various angles to help me grasp what you have done. Thanks!

 

[TOY BOAT]

Mine produced a rooster tail as well. It was mounted correctly.

 

[captnchris]

whistler.........Marine electronics manufacturers we depend on are the best in the world and that's exactly what they do. They build high quality electronics, they don't install them. In fact, troubleshooting installation and optimization of your transducer will comprize the majority of all marine electronics related issues. I would rather believe they are not "passing the buck" because there are so many factors that create the inevitable issues which can occur before the transducer is ever installed. If it isn't the damage the installation creates, it most certainly will pertain to the sounding. Your high speed transducer is purposely designed to skim or "surf" to operate at spec. That said, I do defend them, as the manufacturers provide the basic information and installation equipment (with disclaimers and caveats) and I fail to believe they have any other motive than to provide information as they understand it and have been trained to disseminate.

Oftentimes, the simplest solutions and reasons for causes are the least obvious and, of course, the least understood when it pertains to the installation and optimization of external trailing transducers. These high speed x'ducers are skimming transducers, not plowing transducers. Some find that by installing them as directed below the running surface, they operate to suit...the majority will not. Nature was kind enough to provide displaced and elevating water behind a fast moving planing or displacement hull.

*Note: The Starcraft Islander pictured is not our boat; however, its owner has correctly made his Humminbird installation to operate at spec all in the spirit of avoiding typical hull penetration and damages.

TOY BOAT.......A rooster tail is evidence enough that your transducer is NOT installed correctly. It merely indicates that you have installed it in accordance with its accompanying instructions.

 

[Jonboat Jerry]

I have the 798ci SI combo as well and I couldn't be happier with it. It did take a little transducer tuning to get the rooster tail
down. I also poured over the 798 forum on the unofficial H.B. websites.
https://www.xumba.scholleco.com/index.php
https://forums.sideimagingsoft.com/
https://www.jasonhalfenoutdoors.com/HumminbirdIndex.html

To begin, the washers on the mount have to be set to the correct transom angle. This angle can vary + or - depending on
the angle your boat planes. (The seam on the transducer should be parallel to the water flow coming off the transom at speed.)

To solve the Rooster tail problem, start by getting it up as high as the mount will allow and no 2d signal at speed and no R.T.
mark the location. Adjust the transducer down in 1/16" increments until the 2d reads reliably. There may be a small R.T. but
that's as good as it gets. Other factors are, 455 & 83 khz sensitivity, surface clutter, and noise filter settings.

As for Si and Di, the manual says 2-6 mph are best. The boat has settled into the water and hull turbulence is nil. Chart speed should be same as boat speed.

I have included pics of my setup, you can barely see the seam in the 'ducer. Notice that I have the mount attached to a piece of PVC board spacer that is beveled on the bottom to prevent turb. This gets the ducer away from the transom similar to the offset on a jack plate. I still have a small R.T. but I can live with it.
I'm envious of your sunken boat finds, the only thing around here to look at is ROCKS!

 

[whistler]

I have the 798ci SI combo as well and I couldn't be happier with it. It did take a little transducer tuning to get the rooster tail
down. I also poured over the 798 forum on the unofficial H.B. websites.
https://www.xumba.scholleco.com/index.php
https://forums.sideimagingsoft.com/
https://www.jasonhalfenoutdoors.com/HumminbirdIndex.html

To begin, the washers on the mount have to be set to the correct transom angle. This angle can vary + or - depending on
the angle your boat planes. (The seam on the transducer should be parallel to the water flow coming off the transom at speed.)

I was able to get this set OK according to the instructions given with the unit and how to measure the angle.

To solve the Rooster tail problem, start by getting it up as high as the mount will allow and no 2d signal at speed and no R.T.
mark the location. Adjust the transducer down in 1/16" increments until the 2d reads reliably. There may be a small R.T. but
that's as good as it gets. Other factors are, 455 & 83 khz sensitivity, surface clutter, and noise filter settings.

As for Si and Di, the manual says 2-6 mph are best. The boat has settled into the water and hull turbulence is nil. Chart speed should be same as boat speed.

I have included pics of my setup, you can barely see the seam in the 'ducer. Notice that I have the mount attached to a piece of PVC board spacer that is beveled on the bottom to prevent turb. This gets the ducer away from the transom similar to the offset on a jack plate. I still have a small R.T. but I can live with it.

This is what I'm going to work on. Thanks for the pictures.

I'm envious of your sunken boat finds, the only thing around here to look at is ROCKS!

Yea, I've got to say ROCKS would be boring! It was actually pretty exciting to see the two vessels. I've let my mind wander as to what could be attached to them or is in them and the whole story as to what happened. 60' of water I don't suppose I'll ever find out?