I'm planning to install a shoot-thru-the-hull mount for my transducer. I have an SRQ 17' Le Tigre kevlar canoe. I would like to place the transducer as far forward as possible in the canoe. My question is for those who have actual experience with this set-up. I understand that it is important to choose the thinnest spot, but I'm not sure where that is on my canoe. I'm thinking either up next to the bow bulkhead or under the front seat. Which spot is best? Or is another spot preferrable?

I'm also planning to use silicone caulk, so it can be removed later, if necessary. Thanks in advance!

My transducer arrangement has the unit against the front bulkhead in my Prism.  However, I didn't' put the transducer into a dollop of silicone.  Instead, I took a section of plastic downspout and cut it down to about 4 inches after trimming the bottom edges to conform to the bottom of the hull.  I then used silicone to make a water tight "cup" of the section of downspout to hold my transducer.  When I get ready to put my depth finder into action, I drop the transducer into the cup and add water until the transducer is covered.  I cut a sponge for this purpose and I cut it somewhat larger than the cup so that after use,  it is pushed down into the cup to help anchor the transducer.  The transducer will generally stay in place on all but the longest portages, but I also added a few plastic clips just under the gunwale from the location I use to mount the main unit to the bulkhead.  These clips keep the cable secure and out of the way for loading/unloading packs.  Secondarily, the clip just above the cup on the bulkhead adds additional security for the transducer should it fall out of the cup on a portage.

Of course, you have to add water to the cup after each portage if you want to fish the next lake.

BTW:  I also cut/spliced the transducer cable to eliminate much of the excess cable.

dd

DD,

I assume you feel you are getting good, accurate readings using this set-up.

Old Salt wrote on Apr 8^th, 2011 at 7:29pm:

I assume you feel you are getting good, accurate readings using this set-up.

So far as I know.  I ran the transducer using a side-mount suction cup for a while before I settled on this arrangement.  It appears to me that the degree of signal fidelity is essentially the same.

dd

I have a setup vary similar to DD only in a Magic.  I mounted it as far forward as I could so it would not interfere with packs. Later I noticed there is a thick almost keel where I put the transducer.  I would not have put it there if I had noticed how thick the hull was at that point but it works well.  

Be careful about cutting the transducer wire and getting it connected back that the shielding is kept in tact. I cut my wire down too for a more custom arrangement the first time and ended up replacing the transducer and leaving the full length of wire because the splice seem to cause bad  depth readings, this was seconded by "depth finder rep" who also mention this could happen when shorting the wire.
May be DD has some good tips for a splicing this wire.

Nothing like finding fish that won't bite! ;)

//Windsailor

I went back and check an old post in hopes it had details of the transducer cable splice, but alas it is a bit skimpy on details.

In Feb. 2007, I did the cable splice taking out 10-12 feet of transducer cable.  Once the cable was cut, I removed the rubberized cover from each end for a combined length of about 4".  Then I carefully unwrapped the foil shielding and laid it back down the length of the cable on each side.  (Before doing so, I slid a 4-5 inch length of shrink tubing back down the cable and out of the way.  (Shrinking this over the splice would be my last step in the process.)  

I then measured each of four color coded cables and then cut each one on about a 3/4" stagger with about 1/4" of bare wire exposed for teh soldier joint.  This accomplished a couple of things ... it made the soldier connections in different places and minimized any potential line-to-line signal bleed.  So ultimately the splice points looked something like:

-----/-------------------------
----------/--------------------
---------------/---------------
--------------------/----------

For each splice in turn, I first slide a smaller diameter shrink tube over the longer end of the line to be spliced.  Then I soldiered the line back together.  Finally, I slide short section of of shrink tubing back over the splice and hit it with a heat gun.  (I think a hair dryer would do, but I already had the heat gun from time spent crafting remote control air planes).    I simply repeated the process for the remaining lines.  When all lines were spliced and protected by shrink tubing, I then re-rapped the foil shield.  The final step, was to re-position the larger section of shrink tubing and hit it with the heat gun.

I'd recommend that you make the splice relatively close (a foot or so) to the plug end.  In this position, there should be a little chance it would get submerged in the water (just in case the splice is not water proof).

dd

FWIW I have been told that if you call customer service at Eagle/Lowrance they will send you detailed instructions for shortening a transducer cable.
Proceed with caution and don't change your mind.

FWIW, I'm not planning to splice the cable. I'll just coil excess & ziptie it.  [smiley=dankk2.gif]

I siliconed mine in below the bow seat.  Works great.

The transducer that came with my current detector has a round bottom designed to give accurate readings up to 40 MPN and has enough cable to reach from the bridge to the stern of a big boat.  I bought one from the manufacture that is for mounting on a trolling motor. It has a flat bottom and less cable.

I was a cable builder for 13 years.
dd's explanation/diagram was spot on.
The only tip's I might add is that they make a waterproof shrink tubing that has a glue/sealer inside. I/we would also use a short section of medical grade silicone tubing that we would put over the solder connection and then use the water proof shrink tubing cut a 1/2" longer than silicon tubing. The silicone adds a layer of protection at the solder joint and replaces the wire coating you lose when you strip back the ends to splice/solder. In event of any friction in wire lengths in finished cable, the silicone will prevent any abrasion at the solder joint.
We did this for cables for military apps.
Just a upgrade, not an necessity.
Putting the shielding back is a necessity. When you finish your splice, the cable should be as original as when you started for maximum efficiency.

Quote:

Quote from old_salt on Apr 8th, 2011, 2:29pm: I assume you feel you are getting good, accurate readings using this set-up. So far as I know.  I ran the transducer using a side-mount suction cup for a while before I settled on this arrangement.  It appears to me that the degree of signal fidelity is essentially the same. dd

dd,

I'm thinking of buying a Cuda 300 or Lorance X4 and converting to "portable" as described by KF in prior posts.  What made you switch from the suction cup to the 'through the hull' method?  Just curious.

Thanks in advance!

The biggest reason for me to shoot thru the hull is that I don't have to do anything with the transducer when I portage. All I have to do is turn it off and rotate the head. The next biggest reason is that I occassionally knock the suction cup loose with my paddle. The last reason is that I can tell the bow paddler that he is literally 'on fish'.

wrote on May 2^nd, 2011 at 2:43pm:

dd, I'm thinking of buying a Cuda 300 or Lorance X4 and converting to "portable" as described by KF in prior posts.  What made you switch from the suction cup to the 'through the hull' method?  Just curious. Thanks in advance!

Sorry, I missed your question, but Old_Salt's statement would have been my answer ... except I paddle a solo boat, so I can see what is coming up.  

My screen is located on a foot rail, so I don't have to rotate anything to portage.

dd

Gotcha. Good points.  Thanks for the replies!

The last thing I am is an engineer
...but I've just chucked it in the bilge with some water (flat bottom puck).  Don't like the reading?  Tug it back abit with a jerk on the cable.  No silicone needed.
Your milelage may vary.

Ooops..  

I spliced my transducer wire last night and didn't mind the shielding at all.  I just linked the wires back up with electrical tape, and then a gorilla tape second layer on the wire.  I hooked it up and everything looked to be working all right.  Hope so, anyway :-/

gfy_paddler wrote on May 24^th, 2011 at 1:12pm:

Ooops..   I spliced my transducer wire last night and didn't mind the shielding at all.  I just linked the wires back up with electrical tape, and then a gorilla tape second layer on the wire.  I hooked it up and everything looked to be working all right.  Hope so, anyway :-/

I'd seriously consider soldering the wires. Sooner or later the odds are your tape connections will get pulled on and that could cause problems in the field.
A pencil solder gun from Radio Shack is cheap and it's easy enough to do if your not familiar with soldering. Just tin the two ends first and a light touch to blend together. If done properly a solder joint is the same as the original wire.

Thanks for that Tip SoloTripper.  I walk past a Radio Shack every day and will do exactly as you say!