big issue with placement of 3D transducer on the back of a stern I/O drive need HELP

gica

Petty Officer 1st Class
Joined
Feb 24, 2016
Messages
374
So the first picture shows the keel where I am thinking of placing the transducer but there is no flat area there so I would have to create it by either grinding and epoxy or direct epoxy and then buy a flush mount and install there. Don't know if that will affect the water flow to the motor or the boat handling at all so I am asking what do I do. Every video on YouTube is on out-drives. Don't have one but watched it all. Last picture shows the plate I installed that was going to hold the 3D on its left and HDI 50/200..... on the right. I think I rushed into it not realizing the most important thing. No space for the 3D huge one(10") So help please.
 

Attachments

  • 20191017_140121.jpg
    20191017_140121.jpg
    659.6 KB · Views: 0
  • 20191017_140516.jpg
    20191017_140516.jpg
    521.6 KB · Views: 0
  • 20191018_132734.jpg
    20191018_132734.jpg
    307.7 KB · Views: 0
  • 20191016_205330.jpg
    20191016_205330.jpg
    103.6 KB · Views: 0

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,413
3D?

There are side viewing and 360 degree transducers.

What make and model transducer are you trying to install?

Because they sense from the sides as well, side viewing and 360 transducers have very specific orientations relative to the lower unit.
 

gica

Petty Officer 1st Class
Joined
Feb 24, 2016
Messages
374
Thanks for responding I have the Gen 3 unit with Lowrance 3D structure scan transducer that comes with a module. I did contact Lowrance but they didn't get back to me yet. I guess the stern drives are not as popular for fishing. So as you can see in the pictures ther is no way to mount it on transom and not get interference from the engine. so I wanted to see if putting it on the keel line below the drain would cause any problems to the handling or water flow?
The transducer has a cable that splits at the module into trasducer 1 and transducer 2. If I buy another transducer, don't know if it's sold separately, mount them port and starboard and connect one to trasducer one and the other to transducer 2. I don't know if it would work. F..k this is weird.

3D unit:
https://www.lowrance.com/lowrance/ty...oaAph9EALw_wcB

Flush Mount bracket:
https://www.lowrance.com/lowrance/ty...r-flush-mount/

This would be nice but cannot afford it and it's way too much
https://www.lowrance.com/lowrance/ty...thruhull-dual/
 
Last edited:

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,908
I think they make them in the thru-hull style. You can mount them further up fwd in the hull.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,413
Interesting...wasn’t aware Lowrance required two transducers. Garmin and Bird do it with one

Why not put one transducer on each side of the drive?

Going with the 3 in 1 transducer would eliminate the need for the second transducer
 
Last edited:

gica

Petty Officer 1st Class
Joined
Feb 24, 2016
Messages
374
It is one 3D transducer and the cable itself splits in 2. And it does 3D, down scan and side scan.
I don't have a through hull unit to put underneath I only have the 3D one. Is there a way to use 2 of these one on each side with the same module? Or can it be mounted on the keel with a flush bracket and epoxy right below the drain? Will that affect the water flow to the drive and the boat handling?
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,413
It is one 3D transducer and the cable itself splits in 2. And it does 3D, down scan and side scan.
I don't have a through hull unit to put underneath I only have the 3D one. Is there a way to use 2 of these one on each side with the same module? Or can it be mounted on the keel with a flush bracket and epoxy right below the drain? Will that affect the water flow to the drive and the boat handling?
I read through the docs for your unit.

Seems they build the bottom contours using the 3D transducer and plot the fish "diagram" using the broadband transducer.

Know for sure, "broadband transducer must be within 1 foot of structure transducer" which makes sense if they are doing as I described.

Mounting the transducer on the keel exposes the unit to possible damage. Could make that branch you just ran over awfully expensive.

Mounting it there may or may not cause prop cavitation. You never know until you try it.

I have a flush mount (B175H) thru-hull roughly 12" off keel and 24" back from the transom. No prop issues, but prop wash is an issue when backing up
 

gica

Petty Officer 1st Class
Joined
Feb 24, 2016
Messages
374
https://www.dropbox.com/sh/emgyn4nrcm1rtxm/AADyaM6osX2hCuKaqnzssPMWa?dl=0

That's a link to my Dropbox since I cannot upload anything here.

So I spoke to Simrad twice and asked if I could get another 3D transducer and hook both of them up to the module one on transducer 1 and the other on transducer 2 respective ports. They said of course it was designed this way blah, blah blah and I should get the side by side and 3D plus down image as if there was only one transducer. Remember mine is an I/O and the drive is blocking the one side of the transducer have to get 2 of them.

So now I have to see where to mount these, I think transom is the best bet unless you think I still have a shot at putting it underneath and building a flat space with epoxy and flush bracket it to it. That would be another $100 in brackets plus epoxy plus whatever. But I think transom is better. I will epoxy a plate on the port side as I did in the starboard side. If I put them on opposite sides port and starboard how far from the middle keel line do I have to go, or do I measure from the blade outer going left and right? Don't know where to measure and mount it from. Remember I also have to mount the HDI on the starboard one foot away from the 3D.

This guy here recommends putting the 3D right under the engine.
https://www.youtube.com/watch?v=2m9JQp_RXJA

Thanks in advance for the help
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,413
I find it hard to believe your driveAn awful lot of time and effort
 

gica

Petty Officer 1st Class
Joined
Feb 24, 2016
Messages
374
It's a midlife crisis effort. Plus a bunch of not so hands on friends that are looking forward to the experience.
Anyways let me know if you have anything to add and thanks
 

4now04

Seaman
Joined
Sep 25, 2010
Messages
53
I installed a Gen 1 Lowrance HDS-8 with sidescan on my Four Winns 268 in 2012 or 2013, as you are doing. I installed the Transducer mounting board like your picture shows, except mine is on the left side of the outdrive. I sealed the board to the transom with 3M 5200 to prevent leaks. I also installed the normal transducer just outboard of the sidescan transducer. They do not interfere with each others' signals. The only thing I notice is that the the sidescan transducer on the left side may be only slightly limited in showing shallow targets on the right side of the boat due to its mounting height compared to the outdrive, but this has not been an issue. Imagine a line from the sidescan transducer extending past the bottom of the transom shield part of the outdrive. This may affect the top 10 degrees of the sonar signal on that side, but that's about all.

Installing the longer sidescan transducer under the drain plug would interfere with the outdrive. Cutting holes in the hull is not always desireable. Using the transducer board enables you to change transducers and sonar units in the future without more holes in the boat. Just make sure the bottom edge of the transducer board does not extend below the bottom of the hull.
 
Top