Transducer Location

[slader99]

I can't mount my transducer on the starboard side =(. I know port side isn't ideal but due to other restrictions (main steering and internal fuel tank forcing kicker to port side) I need to mount transducer port side.


Can you guys take a look at the two locations I've marked and suggest mounting location? Location is 1 is between the two strakes, location 1 is between the strake and keel. I'm leaning towards location 2 but am worried it will be too close to the main. There won't be phyical interference but perhaps interference from turbulence/bubbles.

Thanks in advance!

Slader99

 

[Dave S]

I'd say 1. Mount a strip of starboard or white cutting board material on the transom and the bottom and if one location isn't great, you can move it without putting more holes in transom.

 

[Birdsnest]

Shoot though the hull. This can be done with the exterior mounting unit. I had a boat for years that was rigged like this and It worked fine. The only problem I ever had was that I did not have it in a puddle of epoxy to the floor and occasionally sand or gravel would get between the sender and the floor or boat bottom weakening the signal. Other than that it fished fine. Marked bait and fish.

Pros:

maintenance free once its in
Awesome sounding at planing speed
No break offs or ware where the wire connects to the transducer.
No flip ups from hitting kelp and sticks


Cons

Potential for less sensitivity.

To answer your question I would put it between one and two centering it on the back of that chine.

 

[profisher]

I would put it 't he chine also for another reason. I've had my trailer rollers smack and break off a transducer on a hard stop on the road...the boat moved ahead just enough to get the roller into the transducer....I"ve moved the boat back a few inches since to prevent this. I had lots of tongue weight so I could go back without harming the towing characteristics.

 

[Hookin'up]

between 1 and 2 just below the chine an inch or two,
or as said earlier, stick it down inside the hull, you do NOT need to use epoxy as this is permanent,
you can use a good marine silicon and it works perfectly and is easily removable if required

 

[Wwunder]

Shoot though the hull. This can be done with the exterior mounting unit. I had a boat for years that was rigged like this and It worked fine. The only problem I ever had was that I did not have it in a puddle of epoxy to the floor and occasionally sand or gravel would get between the sender and the floor or boat bottom weakening the signal. Other than that it fished fine. Marked bait and fish.

Pros:

maintenance free once its in
Awesome sounding at planing speed
No break offs or ware where the wire connects to the transducer.
No flip ups from hitting kelp and sticks


Cons

Potential for less sensitivity.

To answer your question I would put it between one and two centering it on the back of that chine.

I agree, that is the way I have done it on my last two boats. I just cut the end off a tube of silicone and squeeze out a big blob onto the inside of the hull (has to be a single layer of fibreglass, with no core). Then push the transducer into the blob at a slight angle to make sure there are no air voids and straighten it up once in. It stays put, but could be removed easily anytime. I can track bottom at 25 MPH and 250' deep with a basic garmin transducer using this installation.

 

[profisher]

Any installation if done correctly will allow almost all units to track bottom and see really concentrated balsl of feed. However shooting through the hull will eliminate many sounders from being able to detect and show individual fish as you loose some sensitivity. Most of the cheaper recreational units don"t have an excess of transmitting power and only show individual fish in the very best of conditions. To me, seeing where the fish are is critical....I already know where the bottom is most of the time.

 

[Birdsnest]

You want to make sure you push the unit right down against the bottom of the hull right?

Any installation if done correctly will allow almost all units to track bottom and see really concentrated ball of feed. However shouting through the hull will eliminate many sounders from being able to detect and show individual fish and you loose some sensitivity. To me, seeing where the fish are is critical....I already know where the bottom is most of the time.

I think it would be worth trying for the reduction in hassles it creates. If its not great then place it outside. Also, the transducer can be placed backwards allowing your to screw the mount to some structure for stability.

 

[tykkyt e blue]

I have a Airmar p79 shoot thru hull that works 98% as good as the p66 transom mount... Another way to get a good signal is to glue a short piece of pvc tubing or pipe to the hull and then fill the cavity w glycol ( anti -freeze and water 50/50 ) Push the transducer down into coolant then apply a lite sealant to hold the trans into pipe. Its easy to cut out the sealant around trans if you ever need to change out transducer ( instead of sealed directly to the hull. This is exact the way Airmar's mounting sys works. Grinding and sanding the inner surface of hull flat and smooth is important too.

 

[Seafever]

If you are going on the outside...I would go with location 1.

It is not only turbulence from the engine/cav plate etc. that is a factor......there is also turbulence from chines etc.

So don't mount it right over a chine. Mount it inbetween like in your picture. You want to be where the least turbulent water coming off the hull is.

Mounting too close to the engine could produce electrical interference.....but mine is only about 1 1/2 feet from the engine and I don't get any electrical int. at all. But the power wire on mine goes direct to the battery and is not connected to anything else.

I would not lower the transducer "1 to 2 inches " below the end/bottom of the hull. I would have it so that half the transducer is above and half is below. You stick it down too much you WILL get turbulence interference.

 

[eaglemaniac]

As much as I'm reticent to disagree with profisher, I would suggest the spline in between pic1 and pic2. It looks like the perfect spot to me, it's flat and quite simple to adjust for turbulence etc. Good Luck. eman

 

[profisher]

I was also picking that flat spot as well , but just inside of that between 1 and 2 and clear of the trailer roller would be just as good.

 

[slader99]

Hey All,

Thanks for the responses. Just a little bit of history:

Its a HDS7 unit originally with only the stock skimmer. My hull is quite thick hand laid glass, as far as I can tell approaching 1" thick.

Last year I made a waterbox by cutting the bottom off a yogert container, siliconing the container to the hull and filling with mineral oil. Its worked O.k.; I could keep a bottom lock at any speed however I am quite sure I was loosing alot of sensitivity, had to crank the sensitivity well into the 90's to get a decent picture. As the top wasn't sealed I was worried about dirt and other ingress from the bilge.

This year I cut out the waterbox, removed all traces of everything, sanded and applied sicaflex. I was very careful about making sure to have no air bubbles and put it in the same location however the performance was far worse. Seemed to work quite fine at stop or slow troll but any faster than 8mph and I lost bottom with major interference. Could have been the white silicon, could have been a flaw inside the hull, maybe a combo of both. I know that several ducer manufactures specifically say not to use silicon or adhesive (only epoxy) but I gave it a shot as I had heard others had seen some level of sucess. Maybe they have thinner hulls then me or maybe my install wasn't perfect. I've since removed the silicon and completely cleaned off all traces from the skimmer and hull.

I've made a dam with plumbers putty and epoxied the original skimmer in now. I used slow cure and heated it up in an effort to completely eliminate any bubbles whatsoever. I'm also installing a second transom mount ducer (airmar p-66) hense asking for suggestions on mount location. I ended up going between the lowest strake and keel. Most all of the literature I've read suggests the closer to the keel the better (within some limit). When on the starboard side they say within 3" of swing of prop.... I'd say I've got 10" although I'm on the less desirable port side. I don't have to worry about the rollers/bunks as it is well back from those. I hope I'm clear of prop turbulance as well (fingers crossed).

I'll let you guys know how it goes. (and maybe take some pictures too).

Cheers,

Slader99

 

[Birdsnest]

Thanks for the reply. I am interested to see if there is an improvement setting the unit in epoxy. My understanding is it will send and receive though a hard substrate better than if it is passing through variable substrates. That was my understanding of it. Maybe just leave the smooth finish on the unit so that you can tap it off the epoxy if you want to.
On a side note, i was fiddling(trouble shooting) with my transducer last year and I wasn't sure if it was sending and was trying to feel it but it was so slight. For some reason I decided to put my tung on the bottom of the through hull sender. Wow what a surprise I got when I placed my tung on it I heard the loudest tick ever. Its hard to explain but honestly I dont know if it is safe but I had a few others guys at the shop try it and they all were surprised at the intense to the bone tick they heard. My point is that if you want a better understanding of what the signal is you could do it but I know nothing about it so do it at your own risk. I have a low powered unit and while the experience was not painful I would be afraid to try it on a high power unit. just sayin.