Anyone out there try a thru hull transducer mount before?

I hate to be a wet blanket on this idea, but I have one more thing to add then I'll leave it alone.

I really do think this is a cool idea, but one simple fact is that over enough time, every seal will fail. Sooner or later it is going to happen and I think it's important to weigh the risk to the gain. Many folks for years have been successfully using fish finders without cutting holes below the water line. Sure, you might gain a little more sensitivity through the method you're looking at, but is it worth the risk to you? It's not to me.

When that seal fails, it might be just a slow leak that you find after a trip. No big deal. Or, you might punch through a wave and land hard on the other side, or accidentally paddle over a shallow rock that dislodges the transducer or causes the seal to fail completely. Then you've got a major hole below the waterline that you will never keep up with using a hand pump.

Sure, this might never happen to you. But, it isn't unthinkable either, especially as your boat ages, the plastic continues to flex over time, and the plastic becomes more brittle over time. You're always playing the odds when you paddle out, but to me, punching a hole in flexible plastic below the water line reduces the odds. Ultimately we've got to decide for ourselves the level of risk we're willing to take, and you asked for our thoughts. IMHO I don't think the amount of sensitivity you have the potential to gain with a the through-hull mount is worth the risk of punching a large hole below the water line, and I sure would hate to hear about something bad happening to you.

I have now dismounted my soap box.  

I hate to be a wet blanket on this idea, but I have one more thing to add then I'll leave it alone.

I really do think this is a cool idea, but one simple fact is that over enough time, every seal will fail. Sooner or later it is going to happen and I think it's important to weigh the risk to the gain. Many folks for years have been successfully using fish finders without cutting holes below the water line. Sure, you might gain a little more sensitivity through the method you're looking at, but is it worth the risk to you? It's not to me.

When that seal fails, it might be just a slow leak that you find after a trip. No big deal. Or, you might punch through a wave and land hard on the other side, or accidentally paddle over a shallow rock that dislodges the transducer or causes the seal to fail completely. Then you've got a major hole below the waterline that you will never keep up with using a hand pump.

Sure, this might never happen to you. But, it isn't unthinkable either, especially as your boat ages, the plastic continues to flex over time, and the plastic becomes more brittle over time. You're always playing the odds when you paddle out, but to me, punching a hole in flexible plastic below the water line reduces the odds. Ultimately we've got to decide for ourselves the level of risk we're willing to take, and you asked for our thoughts. IMHO I don't think the amount of sensitivity you have the potential to gain with a the through-hull mount is worth the risk of punching a large hole below the water line, and I sure would hate to hear about something bad happening to you.

I have now dismounted my soap box.  

The guys down south started cutting holes in their hulls to install intakes on those in hatch live wells years ago. Fish finders were the next evolution. Some guys have two holes in their hulls. Fishing a holy yak is probably pretty safe in La Jolla, Dana or Malibu in warm water with fifty other boaters around. It might be a different story by yourself in cold water up north.

One of those SoCal guys here.  Was not happy with the reading I was getting so I took the plunge.  Rather than repost all the pics here it is

http://www.kayaksportfishing.com/phpBB2/viewtopic.php?t=8407

Seal is made both with the 3M 5200 and with physical compression of the neoprene

Wow... Thats a first I have seen!  I dont even want a rivit below the water line!

The 6 stainless screws pull the aluminum plate toward the hull, compressing the neoprene.  Plus that 5200 is some of the slickest, stickiest stuff I have ever worked with.  But I did this last August & still going strong.  I will admit I do sneak peeks inside the hull every now & then, just to make sure

I've been looking at this from all different angles and this is my prognosis....its probably not as crazy as some people think it is.  The failure points are obvious and in the event of a broken seal, the most likely failure to occur, at worst you'll have a leak that is coming in slower than you should be able to pump out. Nothing sticks to polyethylene forever, factoring in some hull flex will shorten that time considerably but so long as you stay on top of it and check it before each trip you should be good. Triumph boat hulls use thru-hulls, no reason we can't.

With that being said, its still a big ass hole in the bottom of your boat and the real issue i see is whether or not the ends really justify the hassle of continual inspections (and in my case installing high water alarm, electric bilge, additional battery power, wedge blocks and manual pump....cause thats the only way I'd get on the water with a thru hull). I say no.  The FF's we use are relatively low end and no matter what you demand or expect its not gonna perform any better than a 1-400 dollar ff should perform.  I wouldn't think of going through the hassle of installing a thru-hull ducer until we're talkin 1kw transmitting power at that point the $$ involved is way more than a rational average income , not completely and utterly obsessed kayakfisher person would spend on a fishfinder for a kayak.

I had a hose clamp fail on one of my  one inch thru-hulls fittings on my old bass boat livewell system(my fault,I forgot to re-tighten it while doing livewell pump maintenance) a automatic 500gph bilge pump could barely keep up. We had water coming thru the floor drains before I noticed it. got the boat started, hull was so full I could not get it on plane, but we could drive fast enough to help siphon the water out thru the fitting. Luckily, I was also able to reconnect the hole and clamp, AND I carry a rubber "cork" stopper. After that incident, I install dual 750 gph pumps, one auto, one manual.



 But i would never cut that big of a hole in any boat unless I had several huge bilge pumps or liked to swim. My life is too valuable and there are too many other mounting options.

I thought long & hard about it before deciding to go for it.  I don't have an inside the hull shot otherwise you would see why I am confident in the install.  The six screws go through the aluminum plate over half an inch, which creates a compression seal with the neoprene.  That would be enough for sealing but the 5200 also seals the install, so it would have to be failure of over half of the screws AND the 5200.  5200 is what is used for thru hull installations on the big sportfishers several feet below the waterline.  The person that modeled how to do this on the SoCal sites does professional installs on big boats and has had no problems with this on his kayaks.

Not trying to convince anyone, just saying that I am not taking undue risks either.  I am far more worried about the errant whitecap striking when I have a hatch open for whatever reason.  My PFD is on when my feet leave dry land until they touch it again.

I've tried several setups and the one that worked best for me is this (sorry, no picture available.)  Take a 3 or 4" plastic pvc coupling and cement it down to the inside of your hull wherever you want the transducer to broadcast from with your favorite supergoop.  I like simple silicone because it's removable if you change your mind and I am a simple kind of guy myself.  Then  simply lay your transducer flat down inside and weigh it down with a tobacco sack full of gravel.  Then fill (or almost fill) the coupling with water.  Cover with a flimsy plastic sealer that matches your couplicng and doesn't mash your teeny wires too bad.

It's easy to set up and easy to remove if you don't like the results, but like I say, it's the best performer I've tried.  No way would I cut a hole in the bottom of any boat--not even to drain the water out.

Good luck...

ive been using my new 343c for a couple of months now with an in hull installation.  still not quite where i want it to be but it will do..

After all that you still want more performance. Man you are a hard man to please. At this point I think you need to spend a grand or so on you FF.

Just saw this thread - I'm in the "not worth it" boat. If you must have your transducer in the water, just go with a portable setup with the puck attached through a scupper or attached off the side.

as far as leaking they seem to be holding up pretty well both Bing, and Jim Day the guy that started the transducer in the yaks with this method have not had any leaks.

Would I do it NO but I have a T13

One of the things I LOVE about kayakking is that we all do it our own way.  A lot of people think it is not worth it or too dangerous, but even more people I know say exactly the same thing about fishing out of a kayak.

Upside = slightly-better FF readings?
Downside = your kayak will sink and you may die

I fail to see why this is a good idea. It sure looks cool though!