Just enough PVC pipe to reach through the scupper, bolt down transducer puck. It should look something like this.
To start things off, I fitted the transducer to a piece of 1″ PVC pipe. I have a ton of scrap pieces throughout my basement and garage. I think this piece is about 4″ long in total. To really get the transducer to fit right, I had to put a small notch into the pipe. If you look closely at the photo (click for full size), you can see that the transducer seems to come out of the back of the pipe. That’s because of the notch I had to cut into it. Your transducer may (and probably will) vary from this Lowrance/Eagle puck. From there, I drilled a hole and bolted the transducer to the pipe, and zip tied the cable to it. I did this to my “Cuda”, but I know the steps are all the same no matter which Jackson sit on top kayak (or SUP?) you’re adding a fish finder to. You might need a bit longer piece of PVC for the “Coosa”, and I’m not sure where the “Big Tuna” comes into play. Fortunately, you can do this much and start with a 6″ long of PVC pipe, and just cut to fit as you go.
Cutting the pool noodle to fit. You can use any closed-cell foam for this.
After I bolted the transducer to the PVC pipe, I grabbed one of the many foam pool noodles I have (this is the best time of year to get them cheap. Your kayaks should have several inside to help aid in buoyancy should they get swamped) and trimmed things to fit. The PVC pipe we set up above is larger in diameter than the hole through the pool noodle, so Il needed to expand that. I just shoved another piece of PVC pipe through the middle and called it good enough. Then you’ll need to cut down the sides of the noodle so that it seats inside the scupper of your kayak. Take a little off at a time, and work to keep the hole in the middle of the noodle. In the end, your piece of pool noodle will be almost cone shaped.
Now, split one side of the pool noodle and slip it around the PVC pipe you’ve attached to your transducer. Feed your transducer wiring through the scupper and then install the whole transducer setup, foam, PVC and all into the scupper. Hopefully you’ll find a pretty snug fit. You’ll need to put a little bit of force into things, but once you let go, things shouldn’t move around either. The transducer will have some play, but only because it is supported by foam. Also, make sure the transducer is not protruding beyond the sides of the hull surrounding it. This is a protective measure. Should you get into some skinny water, pass over a tree or rock, etc., the hull will hit the obstruction, NOT your expensive, not-near-as-durable transducer. The transducer should just “suck up” inside the scupper and be well protected. Jackson Kayak builds the scuppers on their fishing kayaks oversized for this very purpose.
So, if everything is fitting OK, pull it all back out. If things aren’t fitting OK, then make the necessary adjustments until they are. Don’t forget to flip the kayak right side up and take a look at the PVC pipe coming out of the top of the scupper. I like to keep the PVC lower than the flattest part of the kayak or, better yet, a quarter or half inch below the lip of the scupper. This will keep some of the water draining usefulness of the scupper and keep the PVC pipe from becoming an obstacle when it comes time to fish. If the PVC pipe is sticking up, then just pull things apart, cut off as much as you need to, and test fit things again.
Once you’re satisfied that your fitting is good, you can make this more permanent. This step, in my opinion, is totally optional. I like to get some Amazing GOOP® “Marine” formula into the situation, so that I know things aren’t going to fall apart. All you need is a dab on the outside of the foam, and then just a little on the inside of the foam. Take note of where the foam seems to make the firmest, most secure contact with the kayak, and put GOOP® in this area. Likewise, inside the foam, make sure that you’re only applying GOOP® to the area where the foam will make contact with the PVC pipe, NOT the transducer cable. What’s really nice about this whole setup and the GOOP® is that we’re making a semi-permanent installation. It will stand everything you might throw at it, but if you realize you installed your transducer into the wrong scupper (did I do that??) or wish to remove it altogether, everything will come apart with relatively little force. That’s one of the reasons most kayak fishermen love Amazing GOOP® Marine so much.
Now it’s just a matter of putting everything back together and letting it dry.
On the topside of the kayak, when it comes to what to do with the cable, there are a couple options. Many folks have installed this very similar setup on the front most scuppers and just run the cable into either the day hatch on the Coosa or the center hatch of the Cuda. I’m going to be installing a waterproof cable pass through into the hull just forward of my seat.
With the transducer installed in the scupper, it’s now time to deal with all the cable, wiring up the battery, and getting things finished up. I spend a good amount of time in the surf, so I want to make sure my installation is watertight. A number of other folks have routed the cable under the lip of the center hatch on the Cuda. However, this creates a large area for water to get into the kayak, and I’d rather avoid that. My solution uses a waterproof deck fitting made by Ancor Marine. These wire fittings are made to seal up around wires going in/out of boat hulls. Most people will be good with the 1/2″ NPT sized fitting, but measure your sonar plug to make sure. There are a few parts to the fitting: the main body (which includes the wire seal and O-ring), a smaller nut that secures the fitting to the kayak from the inside, and a larger nut that creates the seal. The large nut is internally conical, which creates the compression used by the seal in the body to secure the wire. It’s a pretty slick design and quite inexpensive.
Before making holes on the kayak, it’s really time to find out where to best install the fitting. Because I run my anchor trolley and cleat on the left side of the kayak, I installed the transducer on the right side to reduce clutter. I also want to make sure to keep the wire from the transducer out of the way, so it’s best to install the through-full fitting on the nearest flat surface you can find. I installed mine on the side area between the scupper and the bungee keeper for one of the rod stagers. The transducer and fitting are immediately in front of the seat and plenty out of the way. To install the fitting, you are also going to need a pretty large hole–21mm would be ideal but, seeing as I have a severe shortage of metric drill bits, I went with a 3/4″ bit and filed out the hole a little bit larger. By going this route, I was able to keep expanding the hole ever so slightly until I could actually screw the fitting into the hull. This, with a little added bit of silicone, makes a very nice water-tight seal against the kayak. There is also the rubber O-ring to give even more waterproof protection. Once the fitting is in the hole, reach through with the smaller nut (feel free to give it some silicone around one side if you’d like) and firmly make the fitting permanent. I used a pair of large crescent wrenches to make sure things were tight – just don’t go overboard and damage the fitting.
Now it’s all about feeding the cable into the kayak. Of course, sonar manufacturers supply A TON of cable, but they’re not all that accustomed to guys putting these fish finders on kayaks. No, don’t even think of cutting and splicing a transducer cable. There’s too much going on inside to get it back together again. Just feed the plug through the nut, then the rest of the cable, then feed the plug and cable through the fitting. Once you have everything inside the kayak, and the cable between the fitting and the scupper just the way you want it, then slip the outer nut onto the fitting and tighten it down. Again, you’ll probably need a wrench to help you out. You want to get this plenty snug around the cable. This is the final waterproofing seal and Ancor Marine says if you do this right, the seal is good for upwards of 300′ of submersion. Ideally, if you get this part right, your kayak will never be down at 300′ to test it out.
Time to move inside the kayak. To make life easy, I coil up all but the first three feet of the transducer cable. I secure it with some hook-and-loop wire ties, then attach the coil to one of the scuppers with more hook-and-loop wire ties. This keeps all the cable out of the way, and prevents it from tangling with the rods I store in the kayak. Things can quickly become a mess if left loose. Now, we need to attach a battery and run the first three feet of cable to the head unit of the sonar.
I run a decent sized battery, a 12 volt 8 amp brick. Yes, I could use a smaller one, but I’m pretty bad at charging the battery and this will give me weeks of use before it dies. A lot of guys like to make small battery packs out of AA batteries but, again, I’m not all that great at getting them back on the charger after a single day of fishing. In any case, it’s good to have some sort of container for the battery so it’s not directly exposed to all the elements.
My old kayak had a canvas bag that was meant to hold the battery. The problem is that it also held onto water and didn’t like the idea of drying out at all. As such, the terminals on the battery corroded and things just weren’t good. Instead, I use a cheap food container. For brick batteries, most containers around 2 quarts in size will be ideal. This gives plenty of room for the battery and the wiring and fuse to go along with it. Your fish finder should have come with the inline fuse holder. If not, go to an auto parts store and get one and a 3amp fuse to go with it. Without the fuse, you run the risk of electrical fire, which will be no fun, even if there’s plenty of water around. I also coat every electrical terminal and connector with Sanchem, Inc.’s NO-OX-ID. NO-OX-ID is an electrical connection grease that will prevent corrosion and is packed with metal shavings so that it will conduct electricity. It’s awesome stuff that I’ve been using for a long time on my cars, and now on my kayaks. It’s not cheap, but better than anything else on the market. Apply conservatively to all your electrical connections so they don’t rust or crust up with salt. Fortunately, a little bit goes a long ways.
I drilled a pair of small holes about 1/2” apart on one side of the container–about the same size as the wires connected to the battery. I made my own wire for the ground terminal to make up for the fact that it doesn’t have the in-line fuse like the positive side. With a small slit between the holes, I was able to push the terminals through (should have attached those AFTER I ran the wires out the side). I know a lot of guys use waterproof boxes for batteries, and I mentioned some problems with canvas battery holders. The food container isn’t going to be waterproof, but it will serve to keep things mostly dry. The way I see if, if I have enough water inside my kayak to be causing problems with the battery and electrical stuff, then I have much larger things to worry about. All I’m looking for is a little bit of protection that won’t be absorbing moisture either. The food container was, in my opinion, the best option.
I have chosen to install my sonar on the hatch of the Cuda. So far it hasn’t gotten in the way for me, and I have no problems getting in and out of the hatch. The base of my fish finder covers up the large 1/2″ hole needed to pass the cable through the hatch. Once the base is installed and the cable routed, I filled things in with silicone to get a good seal. Should water come in through here, it’ll be caught in the tray of the Cuda center hatch, and it won’t amount to much water either. I use the tray to keep the cables out of the way, and I’d say things work out just right for me.
To finish things up, I decided to better secure the battery box. While it has a pretty tight fit, the battery weighs in around 5 lbs. It wouldn’t take much of a jostle to send the box flying out of its little home between the scuppers. The solution was a length of bungee cord I had laying around. I wrapped it around the two scuppers and across the front of the battery box and tied it off. It’s important to make sure the bungee is tight enough to keep the battery box secure, but that there is also enough play to get the box out so you can charge the battery before your next trip.
If you’re installing your sonar on the hatch of your Cuda, then you’re done! Let’s say, however, that you don’t want your sonar on the center hatch. Maybe you’re installing your fish finder onto your Coosa. If that’s the case, then there are just a couple more steps. With the Coosa (I know, I should go down and take photos, but I’m feeling lazy at the moment and trying to get this done before a fishing trip), decide on where you want to mount your fish finder. I like mine up between me and the Day Hatch. There’s an oval here intended for the Tallon Accessory Socket, which is a great setup. Install the Tallon sockets in the various ovals, and you can easily move rod holders and electronics mounts wherever and whenever you need. They can get pricey though. I have a YakAttack “MightyMount” installed next to another through-hull wire seal. So, yes, you’re looking at drilling another large hole in your kayak. Keep this fitting close to the mount so there isn’t a lot of excess wire lying about. Install it just like the other. Be mindful of your reach! With the Coosa, there’s not as much interior within reach of the front hatch, or even the Day Hatch. Don’t drill until you know you can get to an area from the inside. You’ll also need to remove the large piece of foam from the kayak to access much of the area where you’ll likely install the fish finder. This foam is a good thing to have. If you need, cut it out to make room for the mounting hardware and put it back inside the kayak.
Don’t want to be drilling as many holes? Or maybe you’re not fortunate enough to have a Jackson Kayak with scuppers built to install transducers? Installing the transducer puck inside the kayak is always an option, and is exactly how I ran my fish finder for years. I cut a piece of foam to fit around my transducer and glued it into place with some Amazing GOOP® Marine. The downside of this method is that I had to put a bottle-cap’s worth of water into where the transducer fits. Sometimes that was a pain. There are other methods similar to this too. Some just GOOP® the transducer right to the hull, while others use some sort of putty. Either way, you’ll still need to install a through-hull fitting next to where you mount your fish finder.
Hope this has been useful