Transducer at high speed

reddog wrote:

https://webapp.navionics.com/?lang=en#boating@14&key=afcqE~oawP

Lake Hamilton is High Def on the Navionics Hotmaps chip, and will run in your H7.

Thanks for looking that up! I just got home from work and was getting ready to look into what maps are available for my Helix… Look like the Navionics has it covered. Much appreciated.
I looked up the spot where I got into trouble before. That spot actually shows up as an island on the Navionics map, even though it was under water by 1-3 feet. I definitely would have avoided that spot (or slowed to a crawl) if I had that map in front of me.
Back to the transducer / depth reading at higher speeds… I naively thought that the manufacturer would not have put a mount in that spot if that was not the “best” spot to mount it. Of course, I guess every transducer / finder is different.

[edit] I suppose the reason the “shallow spot” shows up on the Navtionics map as an island is because it IS an island from late November till early March… The lake level is tightly controlled by the dams at each end… And they just raised it 5 ft from March 1 to March 10, so what “was” an island sticking up 3 feet is now a shallow spot 2 feet deep. I assume it makes more sense to show it at the low level on the maps so people won’t get into 1 foot of water when the map says 6 feet.

Jesse, You can do a highlighted depth with the Navionics chip, but you wont be able to do a depth offset, shallow water setting and multiple colors like you can with a Lakemaster.. But, Navionics is a good option, and much better than running blind, depending on 2D.

Regarding the mount for the transducer. I think its there only because they needed to put one on to avoid putting holes in the pontoon. From a location standpoint, its probably in the best spot, assuming its in the center of the pontoon. Its the gap between the pontoon and the face of the transducer thats going to introduce the cavitation/interference thats going to cause the transducer not to read accurately. If I was told to figure out a way to mount to this vessel that would produce a chance at high speed readings, I would find a way to modify the existing mount to bring the front of the transducer closer to the pontoon, and then set the elevation so the horizontal seam of the transducer is level with the bottom of the pontoon. Adjust elevation and attitude from there. 1/8 inch is a major change when trying to find the “sweet spot”.

reddog wrote:

Jesse, You can do a highlighted depth with the Navionics chip, but you wont be able to do a depth offset, shallow water setting and multiple colors like you can with a Lakemaster.. But, Navionics is a good option, and much better than running blind, depending on 2D.

Are those limitations of the H7 unit he has? Because I think have all those options on the navionics app.

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reddog wrote:

… I would find a way to modify the existing mount to bring the front of the transducer closer to the pontoon, and then set the elevation so the horizontal seam of the transducer is level with the bottom of the pontoon. Adjust elevation and attitude from there. 1/8 inch is a major change when trying to find the “sweet spot”.

Thanks red, that is helpful. From the looks of it, it looks like I could move the bracket to the bottom of the pontoon mounting surface, rather than the back (where it currently is), which would both move it lower AND closer to the toon. It looks like the bracket that came with the ducer is designed to swivel for that sort of positioning if wanted/needed. What do you think?

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It’s been a long time since I’ve used a Navionics in my bird, but yes, I believe the restrictions are Humminbird based. You can do all that with a LakeMaster chip, but those options do not come up in the menu with a Nav chip in.

tangler wrote:

<div class=”d4p-bbt-quote-title”>reddog wrote:</div>
Jesse, You can do a highlighted depth with the Navionics chip, but you wont be able to do a depth offset, shallow water setting and multiple colors like you can with a Lakemaster.. But, Navionics is a good option, and much better than running blind, depending on 2D.

Are those limitations of the H7 unit he has? Because I think have all those options on the navionics app.

tangler wrote:

<div class=”d4p-bbt-quote-title”>reddog wrote:</div>
Jesse, You can do a highlighted depth with the Navionics chip, but you wont be able to do a depth offset, shallow water setting and multiple colors like you can with a Lakemaster.. But, Navionics is a good option, and much better than running blind, depending on 2D.

Are those limitations of the H7 unit he has? Because I think have all those options on the navionics app.

Reddog, what is that line high in the water column on your si picture?

No idea Justin. Sorry

The reason I ask is mine has the same thing and I’m thinking something isn’t quite right with how I installed the transducer.

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Justin Larmay wrote:

The reason I ask is mine has the same thing and I’m thinking something isn’t quite right with how I installed the transducer.

Is it the main motor/turbulence?

I know my trolling motor wasn’t in the water in my picture at 39 mph. Is it possibly your trolling motor?

Negative. Tm was up.