External Lowrance 3-in-1 Xducer (Side Scan/Better Clarity/Accurate Water Temp)

Hey Guys,

I see more and more Stealth anglers wanting to install a through hull transducer in the Stealth kayaks that do not have the recess.  I went ahead and performed the install on my 500.  Attached are some photos and a quick walk through of how I did it.

***I AM NOT RESPONSIBLE IF YOU MANGLE YOUR KAYAK.  THIS IS JUST HOW I WENT ABOUT DOING THIS.***

Tools/materials I used - The links used are associate links.  By using them to get to amazon, even if you don't buy the item in the link, but buy something else, I earn a small commission, but it doesn't cost you any extra.

-Caulking Gun (https://amzn.to/3w7mqo0)
-Drill Motor (https://amzn.to/3FjpyRV)
-1" hole saw for fiberglass (https://amzn.to/3yifhUC)
-Fish tape (https://amzn.to/382FGuY)
-Black marker, easy to see on my hull. (https://amzn.to/3OVKrXU)
-Green Powerpro (https://amzn.to/3vKj23I)
-Sanding Block (https://amzn.to/38NKuEv)
-Sand Paper (I used 320 grit) (https://amzn.to/38584g2)
-Masking tape (https://amzn.to/3KL6op4)
-Electrical tape (https://amzn.to/3OXiaAc)
-Marine silicone FOR USE BELOW WATERLINE (I used 3m 4200 in black) (https://amzn.to/3OQ5gUu)
-Custom 3d printed hole sleeve and cover (seen below) (you can contact me if you want to buy this set, its $25 shipped at the time of this posting)
-Rags, lots of them. (https://amzn.to/382ECY1)

I set my kayak on some saw horses upright and removed everything from the inside.  Then I went ahead and removed the rudder form the kayak.  After it was empty and the rudder was removed, I flipped it over so the hull was facing the sky.

I then took some masking tape and attached a piece of green power pro from the bow to the stern as a representation of where the center line of the kayak was.  Once I had that secured and stretched tight, I placed the transducer on the hull by hand where I thought I might like it and traced around it with the black marker.  I then estimated where the wire would have to pass through, so that it wasn't bent at too hard of an angle, but was close enough that it wasn't going to be a snagging hazard on the bottom, I set my plastic printed clam shell over the wire to get a feel for how it would fit with the wire and that the wire wasnt going to be so close that it was rigid and lifted the shell.  Once I had that lined up, I marked a  center point with the marker where hole would go.  For this transducer it is a 1" hole.

I removed the items from the hull, and used the sanding block and sand paper to rough up the space that I traced with the black marker, I took care here to not scuff anything outside the line.  If I were to do this again I would mark a crosshair in the space that extends out about 6" on either side left to right and front to back, that is directly centered with the kayak from left to right, and centered with your tracing from front to back (we will touch on this in a bit).   

Once that space was sufficiently "roughed" I used the 1" hole saw and the drill motor to drill my hole.  There is a couple of foam runners in the hull, they moved fairly easily out of the way.  I then used some sand paper by hand to clean the edge of the hole so that it would not wear on anything passing through it.

Once the hole was clear I passed the connector end into the hull.  It was to far to go from the hole to the outlet in the fish hatch where I needed to extract it so I had to pull it out and attach it with tape to a fiberglass fish tape.  Once I had that secured together, I fished the connector through the hole and by way of kind of jiggling and rotating the fish tape back and forth I managed to work it up to the hole in the fish hatch,  I unsecured the tape there, pulled the connector out of the fish hatch hole and removed the fish tape through the exterior hole.

The hard part was done.

Now that I had the transducer on the outside of the hull, the wire inside the hull, and the connector in the fish hatch, it was time to secure everything and seal the hole. 

I went ahead and applied a layer of silicone on the bottom of the transducer in an even monotonic order so that it was consistent across the entire mating surface, (I put way too much on it fwiw).  I lined up the transducer with the sanded area and pressed it down.  At this point the excess silicone oozed out and covered my marker lines, so I had to eye ball to try and get it straight.  This where the crosshair would have come in handy for centering the transducer.  I cleaned up everything that oozed out. and left the transducer to set.

I then slipped the sleeve over the wire which was now in the hull and used a short length of electrical tape to make a cone around the "bottom" of the sleeve and the wire (this secured the sleeve to the wire lightly, so I had to put it where it would go once it was installed.)  The purpose of this "cone" was to fill with silicone, so that it didn't just pour into my hull.  Once that was "made up" I made a bead of silicone around the edge of the hull and pressed the sleeve into the hole.  This caused the silicone to ooze out around the lip of the sleeve, that was ok because I wanted it to be secure, and it will be covered anyways.  I then filled the sleeve/cone with silicone sealing around the wire where its penetrating into the hull.  This is what actually seals the hole. and prevents water intrusion.

Once that was installed I filled the clamshell piece with silicon and lined it up where I wanted it to go to protect the wire where it went into the hull, and I pressed it on.  Again, silicone ooze was present so I lightly wiped it away and tried my best to clean it up. 

I let it set for about an hour while I cleaned up and then used a plastic razor blade to scrape some of the excess silicone off of the kayak.  I left enough on there that one can tell it was not professionally installed but it doesn't look terrible, and it keeps the water out, while allowing me to see all the things I couldn't with an in hull transducer.  I have since been out on the water a number of times and I do not take on any excess water with this mod.

Edit:  I forgot to mention that I left my original transducer installed in the hull and sealed the cable,  I can actually run both at the same time with my unit, but I dont want the excess battery drain on the water, however if the external transducer were to break or have issues I can quickly swap to the original transducer.

Thanks for reading.  If you enjoyed this consider checking me out on instagram (@blackflag_fishing) and youtube: https://www.youtube.com/channel/UC8uslKldedfJq90gfelHXRw

3d Printed Components below:

some pics

Nicely done!

Awesome. Thanks for posting this!

Wow, thank you for providing such a detailed explanation of your process. This is really useful for all of us Stealth owners.

I am just now in the process of installing a Humminbird Helix 5 transducer on the inside of my 460. I'll test out the side scan on the Petaluma River this weekend, but from what you have said, it sounds like I may not get great readings. If I can't live with it, maybe I'll give your project a go.

Thanks again.

Nicely done!

Thank you!

Awesome. Thanks for posting this!

Sure thing, Hope it helps!

Wow, thank you for providing such a detailed explanation of your process. This is really useful for all of us Stealth owners.

I am just now in the process of installing a Humminbird Helix 5 transducer on the inside of my 460. I'll test out the side scan on the Petaluma River this weekend, but from what you have said, it sounds like I may not get great readings. If I can't live with it, maybe I'll give your project a go.

Thanks again.

  Thanks.  Good luck with your install.. I don't believe side scan will work inside the hull unless the emissive faces of the xducer are completely covered by some medium besides air.  I am interested to hear your report!

Nicely done!

Thank you!

Awesome. Thanks for posting this!

Sure thing, Hope it helps!

Wow, thank you for providing such a detailed explanation of your process. This is really useful for all of us Stealth owners.

I am just now in the process of installing a Humminbird Helix 5 transducer on the inside of my 460. I'll test out the side scan on the Petaluma River this weekend, but from what you have said, it sounds like I may not get great readings. If I can't live with it, maybe I'll give your project a go.

Thanks again.

  Thanks.  Good luck with your install.. I don't believe side scan will work inside the hull unless the emissive faces of the xducer are completely covered by some medium besides air.  I am interested to hear your report!

You will not get a return through air. So a sidescan installed in hull will not work, even if it is in a water bath. Once it gets past the water it will no longer be able to penetrate. You will be able to use chirp and downscan in hull, but not sidescan unless you get really really creative.

You will not get a return through air. So a sidescan installed in hull will not work, even if it is in a water bath. Once it gets past the water it will no longer be able to penetrate. You will be able to use chirp and downscan in hull, but not sidescan unless you get really really creative.

Good to know. So how important is side scan for fishing halibut, salmon and rockfish? I rather doubt I will use it for rockfish....

It helps you find bait and can help with larger fish that are outside of your cone, but If there are big fish on the surface you will see signs and if they’re deep you will see them in your sonar cone.  Def more of a thing for bass fishing.

Nicely done!

Thank you!

Awesome. Thanks for posting this!

Sure thing, Hope it helps!

Wow, thank you for providing such a detailed explanation of your process. This is really useful for all of us Stealth owners.

I am just now in the process of installing a Humminbird Helix 5 transducer on the inside of my 460. I'll test out the side scan on the Petaluma River this weekend, but from what you have said, it sounds like I may not get great readings. If I can't live with it, maybe I'll give your project a go.

Thanks again.

  Thanks.  Good luck with your install.. I don't believe side scan will work inside the hull unless the emissive faces of the xducer are completely covered by some medium besides air.  I am interested to hear your report!

You will not get a return through air. So a sidescan installed in hull will not work, even if it is in a water bath. Once it gets past the water it will no longer be able to penetrate. You will be able to use chirp and downscan in hull, but not sidescan unless you get really really creative.

This is what I thought as well.  However, I do get some amount of reading when the kayak is on the wall in the garage.  I can wave my hand past it outside the hull and get a return.

Follow up question before I go too crazy, have you noticed any real world difference in paddle speed and efficiency? I know that there will be some added drag anytime you are hanging things off the hull, but I was wondering how much?

Follow up question before I go too crazy, have you noticed any real world difference in paddle speed and efficiency? I know that there will be some added drag anytime you are hanging things off the hull, but I was wondering how much?

I have not noticed a difference.  It has been out 3x since the install and I still note great speeds on my ff.  It’s fairly hydro dynamic and While I consider myself a pretty good paddler, I don’t think I am at the level where I would notice a difference from the xducer.  Additionally, I am typically towing a nomad dtx140 or other 30’ diving plug behind the kayak that adds massive amounts of drag so I don’t think I would feel the xducer with that out.

You drilled a 1" hole in the bottom of your (expensive) kayak? That's impressive.

Not me, but a lot of people balk at drilling a 1/4" hole in their rotomolded yak above the waterline! People like that would probably faint at the mere thought of  a 1" drill bit anywhere near the bottom of a kayak...

You drilled a 1" hole in the bottom of your (expensive) kayak? That's impressive.

Not me, but a lot of people balk at drilling a 1/4" hole in their rotomolded yak above the waterline! People like that would probably faint at the mere thought of  a 1" drill bit anywhere near the bottom of a kayak...

I wish it was only 1”