How to fit a transducer & a sounder to a kayak

We had made quite a few casts along the bank with minimal results. I had noticed on my Humminbird sounder that the odd fish was marking up on the bottom as I made my way down the bank. I started to wonder whether the warmer water had maybe pushed the fish away from the bank and they had moved in search of the cooler water that the deeper sections of the river provided.

I paddled out a bit further from the bank and focused my attention on my sounder. The water depth slowly dropped a few feet and fish started to mark up. I made a quick lure change opting for a lipless vibration lure. I position the boat in the main river and made my first speculative cast down the middle. I hopped the vibe and then let it fall back to the bottom. It never made it there. The line flicked and the rod immediately folded over. The fish surged away pulling drag as it went. I managed to keep it away from the numerous snags that dotted the bank and shortly after lifted a great looking river bass into my kayak. From then on the snags on the bank were forgotten and instead we targeted the fish holding down the middle of the river. The sounder had definitely been the key to unlocking the pattern for the day.

A sounder is an integral part of most boats. If you fish out of a boat, you generally have one. Sounders give you an insight into the bottom you are fishing over, the temperature of the water and whether or not there are fish under or around your boat. Kayak anglers don’t often have the luxury of a sounder in many of their watercraft, but this is changing rapidly- with more kayak anglers realising the necessity of a sounder they are fitting them to their boats. It is actually not that hard to do-IF you have access to your boats hull.  Let’s take a look at the step by step process of fitting a sounder to your kayak.


Here’s what you need:

  • 1 x Humminbird transducer
  • 1 x Remco RM12-7.2 sealed battery (12V)
  • 1 x small battery tray with elastic tie-down
  • 1 x Aquaseal Marine Sealant – mSEAL 595 clear (BLA sku: 264156)
  • 1 x Septone acetone (BLA sku: 261260)
  • Some sanding paper

Step by step:


You have checked your boat and found that you will be able to fit a sounder. You have the unit and are ready to go. There are a few things that will be a necessity to fitting it. A sounder would require battery power, so a battery and a battery storage tray would be the most important. Small 12V batteries like the Remco RM12-7.2 sealed battery is a great choice. It is a small light weight rechargeable battery that won’t take up too much space when fitted. A small battery tray with an elastic tie-down will be all you would need to store the battery. Add to this some marine sealant to glue these parts to your boat, some sanding paper and a cleaning agent like Acetone and you are ready to go.

Try to position the transducer about amidships on your kayak, if this is not possible then mount it in a safe place that doesn’t get a lot of stuff thrown in on top of it. This would just safeguard your transducer against any damage and once you had it in you would want to keep it working properly. The battery would also need to be close to the middle of the boat but in an easily accessible spot to ensure that you can put in and take it out at the start and end of each trip.


Prior to gluing anything to the hull give it a good sand with the sandpaper to rough up the surface as much as possible. Be wary though that you don’t go too hard as you can damage the integrity of your kayak. Once you have roughed up the area for your battery tray, clean the area with the acetone and allow drying.





You can then apply a liberal amount of the marine sealant to the tray and glue it to the bottom of the hull. The transducer can be mounted in a similar way. Simply apply a liberal amount of sealant to the base off the transducer and stick it to the hull. Make sure that there are no bubbles or trapped air under the transducer as this will inhibit its ability to read the bottom.

Also try to make sure that the transducer is level so that when the boat is floating the transducer will not be at an angle, but instead be shooting straight down.

Your kayaks hull also needs to be made of a solid material with no air in the hull. If there is air or foam in the hull then you will need to look at mounting the transducer off the back of the boat, or somewhere else where it is in the water on the outside of the boat. If you are unsure of the core of your boats hull a trial on the water will sort this out before you do any gluing of the transducer.



You can now run your power lead from your sounder to your battery. A set of push on terminals will make for easy on off usage as you would not want to transport your boat with the battery in. Keep you wires neat and tidy and secure them to your hatch lid or other spot to stop them moving around. This inhibits damage and keeps them out of the way. You will need to leave the sealant for at least 2 days to cure properly and thus ensuring a good solid bond. The last thing you want is for your battery tray or transducer to pull loose on the first outing.




Once your wiring is secured to where your sounder is going to be you can mount your sounder bracket. A hole saw can be used to drill the access point for your wires. Just remember to keep the hole size to a minimum.




Run your wires through the hole and up into or through your bracket. After ensuring that everything fits you can mount the sounder bracket permanently. Most of these brackets generally come with some self tapping screws and you can simply screw them down to the boat. The boat that we used for our demo pictures is the Ocean Kayak Tetra, and it actually has a nice hatch that you can mount your sounder on top of. The inside of the lid to this hatch has sufficient space to secure the excess wiring with tie straps. Have a look at the way that the wires have been secured and see if your boat has a similar lid to this. If not then you can secure the wires with an alternative method.

Try to mount the bracket in a spot that is easily accessible but not protruding from your yak as overhanging branches or the odd collision with the bank could end in the bracket being broken or even pulled off. The good thing with the bracket is that the Sounder can be removed and placed in the car during transportation. Be wary of the sounder bracket when loading your yak on and off your roof racks or trailer as they can easily be damaged when doing this; especially by mates that haven’t loaded your boat before.




Once you have the bracket in place, connect the wires to the sounder, fit your battery and switch it on. Most sounders have a simulator mode that you can run just to see if all is working. So you have now tested the unit and it is working.

The next step would be to find some water and test the unit to see if it is actually working. If this is the case you are ready to go. Always remember to recharge your battery before each trip to give you trouble free sounding, and very importantly never transport the battery for your sounder in your yak. The weight of the battery and the movement of the car will often tear the tray loose.

All you need do now is head out on the water and enjoy your sounder for what it was meant for, and that’s catching more fish.