Adding Transducer Sonar in Boat (ski locker location) no hole through hull

[Seadoo20]

Hi guys. I want to put a Transducer on the bottom of the ski locker at back near the drain hole on a 2002 Seadoo Challenger 2000 with the Optimax 250.
This saves me the trouble of mounting on the hull with a new hole to drill, and running the wires up.
Have read online and spoke with Hummingbird and Garmin about this.
As the transducer is only going through Fiberglass in this location they say it should work.

I only want a depth gauge but for the price of these gauges, entry fish finders are same price, like the Garmin Striker 4 and they also have GPS, give water temp, structure, boat speed, etc.. makes more sense to install.

Anybody try this? Tips ?
Did you use Silicone, Duct Seal, Epoxy, or Squishy Foam for the Transducer to sit in ?
Thanks.

 

[Seadoo20]

As an update.
I spoke with Garmin about this and they told me it would work as long as there was no wood blocking the sonar.
The Challenger ski locker is all fiberglass and a low point so it should work.
I used duct seal for the transducer because it allowed for easy removal if I wanted.
I cleaned the mount area good with alcohol first then laid out the duct seal putty flat with no bubbles.
I then squished the sonar transducer into it.
It was easy to route the wire from the ski locker underneath over to behind the console area, and there was a couple spare positive spades on the electric distribution panel box behind the gauges for the positive wire. With the ground wire for now I clamped onto the ground nut.
I finally had it out on the weekend. Here is a picture. Very happy this worked. Having water info combined with the MinnKota bracket on installed on the front of the boat for the electric motor, makes the boat alot more safe and versatile for me.

 

[Tim75]

As an update.
I spoke with Garmin about this and they told me it would work as long as there was no wood blocking the sonar.
The Challenger ski locker is all fiberglass and a low point so it should work.
I used duct seal for the transducer because it allowed for easy removal if I wanted.
I cleaned the mount area good with alcohol first then laid out the duct seal putty flat with no bubbles.
I then squished the sonar transducer into it.
It was easy to route the wire from the ski locker underneath over to behind the console area, and there was a couple spare positive spades on the electric distribution panel box behind the gauges for the positive wire. With the ground wire for now I clamped onto the ground nut.
I finally had it out on the weekend. Here is a picture. Very happy this worked. Having water info combined with the MinnKota bracket on installed on the front of the boat for the electric motor, makes the boat alot more safe and versatile for me.

Glad it works for you. I could never get that mounting to work for me.

 

[Seadoo20]

Glad it works for you. I could never get that mounting to work for me.

Without knowing the specifics of your install here is what I learned during my install.

There are different types of sonar transducers.
It needs to be the simple type that just does vertical up and down and not sideways beams.
Sideways beans will be affected by the boats hull.
A simple transducer like what is mounted on the inside of kayaks and canoes.

Contact tech support for the brand - there are only a few main ones.
Give them the model number of the fish finder. They will verify if the sonar it comes with should work.
I did this before I bought this unit.
I can say the tech person I spoke to, did not know the answer and she thought it was an unusual install.
She told me she had to do some research and ask a more senior person.
I got an email the next day saying it should work.

Something else I can say for anyone thinking about doing this.
Make sure the mount location will allow for the forward gear lever to engage at the very top of the range.
So put the boat fully into forward gear first then mount it.

I realize that this boat is able to go into very shallow water. A big reason I bought it.
With the dry summer we have had, and the water levels being so low - its important info to have for me.