Pros & Cons of Mounting Transducer in hull vs. out of hull?

Hi All,

Just got into the kayak scene and getting everything rigged up and ready to go, and what do you know my gf comes home with a brand new Lowrance Hook 4HDI as an early bday gift, so awesome...Turns out the transducer is WAY to large to fit in the scupper mount on the bottom of my Malibu Stealth 14. In doing some quick research i see that people mount the Transducer inside the hull toward the front, but others have commented that it interferes with some of the readings to the fish-finder. The alternatives to that is to buy a removable Transducer arm, but I've already put so much money into this thing.

What are some of the pros and cons between the two methods? Is the in-hull option really gonna mess with the  readings to have a significant impact or should i just spend some more money for the arm? All advice is heard and appreciated. Thanks!

That gf sounds like a keeper.

I've tried all popular methods and settled on gooping the transducer inside the hull. The temp reading is not quite accurate, but everything else works great, and it is truly no hassle.

dont do the arm. it will drag/pull you to one side constantly. I have mine ($60 fish easy) glued (lexel) to the inside/front of the hull. It has been through 10 yrs of heavy use.It's been bomb proof for me.
Some peeps make a little bath tub out of foam, glue the foam piece to the inside, fill the hollowed out foam w/h2o, drop the 'ducer into it.

i think one of those arms would be a total PITA. dont over think it, just do it. 

Welcome To The Madness!!

I was in the same boat so to speak as you...not sure where or how to mount the transducer for my Lowrance Elite 4.

I ended up running the cables through the front hatch of my Hobie TI and used Marine Goop to fix the transducer to the bottom of the hull. I cut a 2" deep section of a beer cozy (without the bottom, so just a sleeve, basically) and squeezed the transducer into that, placed it where I wanted it inside the boat and filled the cozy with Marine Goop. Make sure to heat the Marine Goop tube in some hot water to get it nice and fluid so that it will fill out all the gaps and not leave air bubbles.

I used duct tape across the transducer to keep it firm and in place until it dried. It worked perfectly the first time and has been great ever since.

The best part about this technique is that the Marine Goop is not permanent.

Hope this helps.

Thanks a ton for all the quick responses as i'm trying to get this done tomorrow to be ready come sunday & monday. Sound like i'm headed to westmarine to get some Marine Goop and possibly a foam pad.

Quick question though. Is the marine goop just used to hold the unit in place inside the hull? Or would some other method of, lets say it being able to be removable like (velcrod) to the hull be an option, considering the unit is already water sealed? Just wondering if there's some other unknown purpose for the goop i don't know about. Thanks!

You can't have any air gaps. Goop will hold it for the long term but is removable (with effort). Also, save youself some money and buy the goop at HD.

Goop (or Lexel in my case) is needed to ensure the transducer is not shooting through air. Your unit will not operate correctly using Velcro or similar to hold. In addition you have to ensure there are no air bubbles in your adhesive between your transducer and hull. I mounted my Lowrance 4 HDI transducer inside my hull and have been very happy so far. Hassle free reliable operation.


Sent from my iPhone using Tapatalk

I copied this idea, but my mod was I needed the transducer to be removable (b/c I use it on 2+ vessels).
http://www.hammerheadkayaksupply.com/duct-seal.html

At home depot, in the plumbing section, I found this rubber grommet thing I think is made to go around the base of a 3-4" pipe that would come out of the ground.  It is very pliable, which I needed b/c I mounted it inside the kayak where the left half and right half meet (it makes the "V" so point is not flat).  I use Duct Seal putty to attach that grommet to the kayak.  Duct Seal is in the Electrical isle, it is about 6"x2" brick wrapped in white packaging- very dense, pliable, and sells for ~$5 I think.  It does a great job remaining firm, and pliable, watertight for this purpose.  When I hit the water, I drop my transducer in with 1-2 cups of water and it works great (temperature is accurate).



 

Over thought mine and it took over a week to get everything together, watch a ton of YouTube, search through a bunch of NCKA posts on the subject and finally cut the bottom off a piece of Tupperware and goop it in hull with a foam cradle to help seal it and hold the transducer in place.

Works great as long as you remember to put water in the Tupperware, (PITA to fill after you launch). Water temperature reading is (probably) not accurate. The only other problem is I spend so much time playing with the FF OTW that I may be catching less fish that when fishing blind.

Never did find the duct seal  because I thought it was used to seal ducts and didn't look in the electrical section.

Thanks to everyone again for all the info. It was SOOO helpful and very easy. I was way overthinking the whole process...

Finished the install this morning and decided to go with a firm piece of foam which was easy to shape considering the Malibu 14 doesn't really have any flat level surface under the kayak and was able to shape it perfectly to the V-hull. Gooped the hell out of it and now its just the waiting game for it to dry. Fingers crossed i didn't screw it up.

Works great as long as you remember to put water in the Tupperware, (PITA to fill after you launch). Water temperature reading is (probably) not accurate.
Thats why I carry a small pill bottle to fill my foam/transducer install.  I can fill mine because I mounted it inside, directly in front of my center hatch.

Bottom cut out of a tupperware container, used Dicor to glue it down around the edges.  I've used lots of different RTV type adhesives, but nothing really sticks to kayak plastic.  This Dicor does.  It's used on RV roofs to seal the plastic parts up there, like antenna, roof hatch, etc.

I cut a hole and notch in the lid so the transducer cable and go through and the lid still snap down.  Then I sealed where the cable went though.  I filled it with water and it's not lost any water in over 3 months. 

I really like this as I move my FF from one kayak to another.