Are true thru hull transducer worth it ?

I am looking to get a Solix mega + for my lund boat ( aluminium ). I was wondering if a true thru hull transducer is worth it to get the very best picture quality.
I heard that a thru the hull transducer can:
- give you a good reading of side imaging at higher speeds
- aslo you don't get the shaft of the motor to interfer with the SI compared to transom mount ( I know I can get a second transom transducer for that )
- you can get a better reading of the 2 d sonar at higher speeds

Now I know some of you would tell me that it's a big step to cut thru the aluminium hull, but I guess that my boat will always be a fishing boat, and if I change sonars I can re-use the hole that I made.

Thanks
Jack
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The hull's performance would determine if a thru-hull transducer is a suitable application. They are used on non-planning hulls (displacement), but not wise on a high speed planning hull. Just common sense.
Some use the thru-hull on a surface that doesn't have water contact at speed like under the transom extension on a Ranger.

I too contemplated a Thru-hull transducer on my Seaark cause I would lose depth/speed at anything about 7-10mph. I add a 6" jackplate and moved Medga SI+ transducer very close to keel on transom, and I now I get both. Very happy!

So the transducer goes lower in the water when your jack plate is down and it gives u a better image ?

So Wayne, I have a Lund impact 1875 2018, I guess that would be a planning hulls and therefor a thru the hull won't be good ?

BTW, thanks guys for your replies !! :smile:

Quote:

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Originally Posted by Jessyjack10

So Wayne, I have a Lund impact 1875 2018, I guess that would be a planning hulls and therefor a thru the hull won't be good ?

BTW, thanks guys for your replies !! :smile:

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No unless you have a small outboard and can't get on plane.

Have had a thru hull transducer on my aluminum Jon boat for years two different brands with two different transducers and they were no better at keeping bottom contact. 8 -10 mph and I loose bottom contact.

Thanks Wayne,

I have one last question. Why is thru hull not good on boats that get on planes ?
1 - Is it because you will lose the reading when the boat planes at high speeds ?
2 - Or is it because the transducer greats too much resistance at high speeds and could also get damaged ? ( I have a 150hp with - max speed 50 mph )

If it's only because you lose readings at very high speeds, I don't mind because I wouldn't do side imaging at 10+ miles/hour. What I'm looking for is the clearest image ( especially from side imaging ), and if I could do that at 8-10 mph with a thru hull, that would be great

Quote:

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Originally Posted by Jessyjack10

Thanks Wayne,

I have one last question. Why is thru hull not good on boats that get on planes ?
1 - Is it because you will lose the reading when the boat planes at high speeds ?
2 - Or is it because the transducer greats too much resistance at high speeds and could also get damaged ? ( I have a 150hp with - max speed 50 mph )

If it's only because you lose readings at very high speeds, I don't mind because I wouldn't do side imaging at 10+ miles/hour. What I'm looking for is the clearest image ( especially from side imaging ), and if I could do that at 8-10 mph with a thru hull, that would be great

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1. No

2. It's not about damaging the transducer, it's because it can aerate the water going to the prop (cavitation) and also effect engine cooling. AND can affect handling at high speeds.

May can't get any reading at 10 mph with it that high above the hull bottom. The distance between the hull bottom and transducer determines at what speed the transducer will still have water contact. Does help some with it under the step and farther away from the vertical part of the hull there the hull drain and plumbing fittings are. BUT there is a lot of turbulence in that area moving forward.

So your saying that the lost of the readings are primarily due to the fact that the transducer is slightly out of the water or because of the turbulence. So that means if I would place the transducer on a pole and lower it down below the boat hull I should get readings at higher speed than a transom mount?

Look at all the Ranger installation pictures and see how ALL of them are done. Then look at some of the other boat brands to see how they are done.
Parallel with or 1" + or - below the hull bottom would let you go the fastest without cavitation. Certainly no reason to do the pole deal normally.

I do sometimes though since I mess with stuff but would not do this for on-plane use.

https://i.postimg.cc/9FmTfg98/20200320-103005.jpg

Just injecting a video of an install on a boat like yours. I have used this on more than one boat. Current boat gets 2D sonar at 52mph. Si to 7 very clear. With a single SI transducer I trim out my outboard about 10 to 15 degrees and no blockage occurs. At 7 mph there is no downside to trimming out the motor. Bob
https://www.youtube.com/watch?v=zEqV53Mv1jo

Gezz... I just watched the video and it mentions that you must have the high speed transducer higher than the SI imaging one. Mine has been installed the opposite way. Should I get this changed ?????
Attachment 402883

Quote:

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Originally Posted by Jessyjack10

Gezz... I just watched the video and it mentions that you must have the high speed transducer higher than the SI imaging one. Mine has been installed the opposite way. Should I get this changed ?????

Attachment 402840

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That is done for the reason stated, so the SI pulses are not blocked (much). BUT what is not mentioned is Humminbird's Side Imaging "sees" from the water's surface to past vertical under the transducer on both sides---soooo no matter where the two are some of the coverage will be blocked, just less doing it that way. Also stated was about hull rivets, then the boat pictured has a whole line of rivets across the transom so there is no way to avoid the aeration caused by rivets on that hull.
Better yet is to have the transducers on opposite sides of the keel to lessen the amount of side blockage.

I have that situation. 18 years of installing various transducers and got all of them to work at 52mph. I did add the high speed to make it possible to have the SI ducers up out of harms way after one got destroyed By a piece of 2X4. (Lund Pro-V)