Does placing the transducer on the inside of the kayak interfere with the readings more than having it on the outside?
i was looking at a video and the guy glued it to the inside of the kayak.

Depends on the hull thickness.
Best method for shooting through the hull is with a water well
If you use a water well, the drop in sensitivity is minimal.
Lots of people shield their transducers these days. The transducer shields are made of HDPE (same thing your kayak hull is made out of)

Maybe a 10% drop in sensitivity for 2D (250HZ and under) ; 20% drop for down imaging (900-400 HZ) if using goop method

Personally, I'd much rather shoot through the hull and lose a little sensitivity than hang something over the side

Would like the idea of mounting in the hull rather than over the side. Less hassle, less drag, protected and probably less cost.


On my Jackson Coosa HD, if put in hull would want to put in area under cockpit so I do not loose the bulk of storage area accessible by hatches where I put my ctug cart and dry bag.

How much space would a water well take up?

Also need to get the transducer level fore and aft.


would this work if have a side scan transducer?

Seems if water well is not fully in contact with kayak hull will have some issues also.
With side scan seems would want to mount in center of hull width wise and there is not flat place for a water well in that case.

Use marine goop but you have to make sure there are no bubbles. You will not get an accurate temp read but everything else should be good.

temp. I didn't even think about that.

If done right they work decent but you'll loose the fast accurate water temp reading which depending on how you fish that can be a big loss at times.

If done wrong... well if you can even start over with what you have then it can be a mess. Better see if you can get a replacement transducer first. I tried it once. It didn't work out.


No it will not work with Side Scan.


I have Side Scan and don't have a problem with it hanging over the side. The drag is so minimal that when I stop paddling and glide my kayak will go straight. With the right mount it won't break but just lift over anything you hit. There is no question on the accuracy when mounted outside the hull and water temp readings will be fast and accurate. That reading alone helped me win $$$ in a tournament during the winter so don't ignore water temp readings!

Use a transducer arm and put it in the water. It's not a big deal.

Hard to keep anything stuck to the inside of my kayak the way I load, unload, and drop from time to time.
1/2 pvc is your friend. What brand and model kayak are you looking to put it on?

You'll be fine Gooping the transducer inside your hull; been doing that for years. And the temperature reading will be accurate within 5 to 15-20 minutes, depending on the temperature difference between the air and water.

"If done wrong... well if you can even start over with what you have then it can be a mess. Better see if you can get a replacement transducer first. I tried it once. It didn't work out." I've had to reGoop two transducers in the past . It's easy, just trim the old Goop off and redo it. Just make sure no air is between the puck and the hull. I Gooped the transducer in the hull of my Trident over 8 years ago, and it still works just fine. I had several transducers epoxied to the hull of my bass boat, which was much thicker than your kayak's hull.

Thanks for the info, seeing some of the side scan transducers tonight at cabellas and your inputs relieve my concerns about drag.
What is a good transducer mount that will lift over anything I might hit?
This mount will get the transducer below the bottom of the kayak?
Do you use a "guard/shield" around the transducer?
I assume you mount it far enough from the bow/stern so do not have to worry about anchor line hitting it when wind/current changes?

I found instructions on building a diy transducer arm using square aluminum tubing on the Internet. I built it and it worked well except while going through thick grass but it was easy to raise and lower as needed.

Here are the instructions that I had saved.

DIY Kayak Folding Transducer Arm

Parts Needed:

� 3/4″ square aluminum tubing
� One YakAttack MightyBolt
� Two YakAttack Threaded Knobs (or substitute a 1/4-20 wing nut)
� One 2″ 1/4-20 bolt

Cut two lengths of tubing. The first is to move the transducer away from the side of the kayak. The second is to move the transducer down into the water. Both of these lengths will vary by kayak and how far you wish to have the transducer into the water, but should be very easy to measure for your application. Once the two lengths are cut, drill a hole from top to bottom near one edge of the piece designed to move the transducer away from the kayak. This will allow the MightyBolt to pass through and mount the arm to the kayak. These bolts are 1/4″, so your hole should be 5/16″ or 3/8″.

Now mark and drill a hole from side to side on both pieces of tubing. Theoretically, this hole should be 3/8″ from the top, bottom, and outside edge of the tubing to ensure that the edges of the two pieces are flush when folded or when the transducer is deployed in the water and the two pieces are perpendicular. Attach the two pieces with the long 1/4-20 bolt and threaded knob.

Finally, attach the transducer. The Lowrance skimmer transducers mount very nicely in the inside of the 3/4″ tubing, but your mileage may vary if you�re using a different transducer. This is just trial and error, but using a small saw and file, you should be able to mount the transducer securely. Cutting an additional notch may also allow you to fish the cable through the inside of the tubing rather than having to zip tie it to the outside.

There are several makers to chose from, I like my Mad Frog.

The ideal solution is with a transducer port. My kayak has a recessed transducer port on the bottom of the kayak that accommodates Lowrance transducers. With a third party transducer shield, it will accommodate side scan and Humminbird transducers.

When purchasing my most recent kayak, the transducer port was the deciding factor on which kayak to purchase.

You can replicate the transducer port set up on some kayaks with a through the scupper mount.

On a previous kayak, I did use a DIY modified over the side set up. I didn't like having to adjust it and redeploy it when around vegetation.

I had to put mine over the side on my new PDL. I run a RayMarine and although it has a reccesed area for transducers it will not accommodate the length of the RayMarine.

Its not ideal but has not been nearly as bad as I thought it might be.

Through the hull never felt like a good option to me. One of the main concerns being water temp and intentionally putting water into the hull to increase the reading quality...seemed odd. I like the hull to be dry.

"main concerns being water temp and intentionally putting water into the hull"

There is no need to put water in the hull, and the water temperature readout will be accurate shortly after putting the kayak in the water. The only time you might need to put water in the hull would be if you suspect that you are getting air under your transducer, which degrades the signal. If adding a little water improves the signal, you'd know that you were getting air under the puck, and you need to reGoop it.