I am picking up my new boat this coming week. I ordered a HDS -12 Gen 3 with 3D. As I was looking at the boat today there was only 1 transducer on the transom. When I asked the mechanic he said the was 2 more transducers inside the boat. My question is this correct. On a unit like this is there a structure scan, 2d sonar and a 3D transducer? Will a structure scan transducer work thru the hull?

No, it must be outside on the transom or jackplate and it's a big transducer. You can put your 2d sonar ducer in the hull as a shoot through, but the lss or 3d have go outside.

Are you 100% sure because this is gonna cause problems when I tell them as I have already pointed out some stuff already. Is there 3 transducers or is there 2? I know there is one that is bigger than the structurescan that was on my other boat mounted on the transom. Just want to make sure as things I ordered on my boat weren't done the way I wanted already and it has caused major problems.

100% positive.

1 transducer for 2d sonar (can be either in the hull or mounted on the transom)

1 either lss ducer or the 3D transom mount.


Now let me say that Lowrance does offer many transducers to select from. Get exact models from them tomorrow and post back here. They might be idiots, but if they are then I'm scared to see what they installed in your boat.


Let me clarify now that I have time. Your new 3D transducer replaces the old lss1 or lss2 transducer. No you cannot use both and no, you can not put one in the hull.

So the 3D transducer is both side,down and 3D scan? So I really only need 2 transducers?

The 3D transducer will give you the options of: right, left, left & right, down or 3D view. I've seen pics of the 3D, but I do not have one. Basically it just replaced the lss1/lss2 and added 3D. It also requires a module box for it to work.

The 2 transducers in the hull scares me. What did you tell them you wanted?


Yes, only 2 transducers needed and only 2 will hook to the graph anyways.

I just ordered a HDS-12 gen 3 with 3D. It was mounted at the factory. Hopefully the mechanic was wrong and just the 2d is mounted inside. I'll call on Monday and report back here. I just wanna have my ducks in a row as I have waited 10 weeks for my boat to come in and it still not ready

1. Here is a link for an image of what your 3D transducer should look like.
https://www.gps4us.com/Lowrance-Xdcr-Str...CFYkjgQodQtoFKg
It has to be mounted somewhere outside of the boat.
2. The 2D transducer can be epoxied inside the boat in the bilge area. If you have two (2) inside they have put in an extra transducer for you. Perhaps an 83/200 and 83/200 HDI?
3. Here's how I set up my Ranger:
a. 1-Transducer outside for down/side/3d.
b. 1-2d Transducer outside (50/200) This transducer is much stronger in construction and can take much more abuse than the standard 83/200 and is generally used for salt water apps, however the 200 works in shallow fresh water applications too. (Use the 200 setting for shallow water)
c.2-2d 83/200 transducers epoxied inside. I normally use one of these for 2d images and always have one for a spare just in case and the 50/200 outside is also used as a spare or when I really need best possible 2D images with no loss with one of the shoot thru hull units.
d. Keep in mind you will have to always adjust and select the type transducer you are using to show the best images on your Gen3.
e. If in doubt, I would ask the dealer to show you exactly where and how many transducers were actually installed on your new boat.
f. When in doubt call Lowrance. They have excellent technicians.

According to the dealer there is just 2 transducers. The 3D is outside on the transom. Ill prolly redo it when I get it home( been waiting going on 12 weeks) with a epoxied plate on the transom.