Kayak Thru Hull Transducer - Kayak Fishing Adventures on Big Water’s Edge

peguinpower · 02-04-2009, 09:37 AM

After hearing so many reports of better fish finder performance by hanging transducers over the side of the kayak, I decided to try it for myself. Try I did but with a more "factory: approach

First of all, some research. Here is what Lowrance has to say about thru the hull installs with purpose built Txs.

"Your unit may read erratic depth with a Shoot-Thru Hull Transducer if the transducer is not intact or if you are using the wrong kind of epoxy. The main reason why you are getting erratic depth with your Shoot-Thru Hull transducer can be traced back to the way the transducer is installed.

Shoot-thru-hull transducers are epoxied directly to the inside of fiberglass boat hulls. The sound is transmitted and received through the hull of the boat - but at the cost of some loss of sonar performance. (You won't be able to "see" as deep with a shoot-thru-hull transducer as one that's mounted on the transom.) The hull has to be made of solid fiberglass. Don't attempt to shoot through aluminum, wood, or steel hulls. Sound can't pass through air (rotomolded kayaks can have air bubbles in the hull), so if there's any wood, metal, or foam reinforcement, it must be removed from the inside of the hull before installing the transducer. Another disadvantage of the shoot-thru-hull transducer is it can't be adjusted for the best fish arches. Although there are disadvantages to a shoot-thru-hull transducer, the advantages are considerable. One, it can't be knocked off by a stump or rock since it's protected inside the hull. Two, since there is nothing protruding into the water flow, it generally works quite well at high speed if it is mounted where a clean laminar flow of water passes over the hull. Three, it can't be fouled by marine growth."

So I pulled out my my old tx. Despite working very well, I guess it was not a perfect installation.

Here is the new unit I'll be putting in.

Onto the installation....

pilot hole

firing up the Ryobi

builder's remorse

hole

clean up. also used acetone. 5200 doesnt like alcohol

test fit

secured with tape before working on the inside

bolting the inside down

before cleaning up the 5200

completion......sea trials on saturday

this project is not for everyone. my kayak is out of warranty. you may or may not have the skills to work stuff like this, find a professional marine installer. you may or may not want a better FF picture, all the best to you. if you are afraid to work below the water line, that's your issue. I always carry a hand action bilge pump. dont be hatin

thanks to our LA County locals for doing it first. Humminbird also helped a lot by providing tech help and advice over the phone.

02-04-2009, 09:37 AM	#1
peguinpower bing! Join Date: Mar 2007 Location: socal Posts: 246	Kayak Thru Hull Transducer After hearing so many reports of better fish finder performance by hanging transducers over the side of the kayak, I decided to try it for myself. Try I did but with a more "factory: approach First of all, some research. Here is what Lowrance has to say about thru the hull installs with purpose built Txs. "Your unit may read erratic depth with a Shoot-Thru Hull Transducer if the transducer is not intact or if you are using the wrong kind of epoxy. The main reason why you are getting erratic depth with your Shoot-Thru Hull transducer can be traced back to the way the transducer is installed. Shoot-thru-hull transducers are epoxied directly to the inside of fiberglass boat hulls. The sound is transmitted and received through the hull of the boat - but at the cost of some loss of sonar performance. (You won't be able to "see" as deep with a shoot-thru-hull transducer as one that's mounted on the transom.) The hull has to be made of solid fiberglass. Don't attempt to shoot through aluminum, wood, or steel hulls. Sound can't pass through air (rotomolded kayaks can have air bubbles in the hull), so if there's any wood, metal, or foam reinforcement, it must be removed from the inside of the hull before installing the transducer. Another disadvantage of the shoot-thru-hull transducer is it can't be adjusted for the best fish arches. Although there are disadvantages to a shoot-thru-hull transducer, the advantages are considerable. One, it can't be knocked off by a stump or rock since it's protected inside the hull. Two, since there is nothing protruding into the water flow, it generally works quite well at high speed if it is mounted where a clean laminar flow of water passes over the hull. Three, it can't be fouled by marine growth." So I pulled out my my old tx. Despite working very well, I guess it was not a perfect installation. Here is the new unit I'll be putting in. Onto the installation.... pilot hole firing up the Ryobi builder's remorse hole clean up. also used acetone. 5200 doesnt like alcohol test fit secured with tape before working on the inside bolting the inside down before cleaning up the 5200 completion......sea trials on saturday this project is not for everyone. my kayak is out of warranty. you may or may not have the skills to work stuff like this, find a professional marine installer. you may or may not want a better FF picture, all the best to you. if you are afraid to work below the water line, that's your issue. I always carry a hand action bilge pump. dont be hatin thanks to our LA County locals for doing it first. Humminbird also helped a lot by providing tech help and advice over the phone.