Sounder Transducer Mounting

[panasonic]

Not engine related.

How many of you mount on the transom or mount inside and shoot through the hull?

Just curious..

[Jason2tpa]

My transducer is mounted on a transom saver block, which is bonded to the transom.

[dray0151]

Mine is currently mounted on the transom for the dash depth/fish finder but I have been considering an inside the hull one for a front depth finder only so I can actually tell how deep it is right in front of me. Would like to know how well those mountings work thru a fiberglass hull. I think you have to have a special transducer for an alum boat because of the hull.

[panasonic]

Mine is currently mounted on the transom for the dash depth/fish finder but I have been considering an inside the hull one for a front depth finder only so I can actually tell how deep it is right in front of me. Would like to know how well those mountings work thru a fiberglass hull. I think you have to have a special transducer for an alum boat because of the hull.

Mine is mounted inside. A piece of 4" PVC pipe about 5 inches high bonded to the hull with 4200. Transducer is epoxied to the bottom, inside the PVC pipe, with slow cure two part epoxy. Fill the pipe with water to cover the transducer and a PVC cap to keep the water from sloshing out.

Asked several people while out on the water what their depth sounder was reading (transducer on the transom) and mind was always very close to theirs, usually within a few feet. In shallow water where I could measure to the bottom with an oar....it was bang on the money.

You just have to find a good spot on the hull where there no voids in the fiberglass, bit of trial and error.

[99yam40]

I do not think they will shoot thru a metal hull or a real think glass hull very well.

the real thick glass offshore rigs I have seen had hole drilled and the units mounted thru the hull

[TownsendsFJR1300]

Mine is currently on the transom but would definitely prefer having it inside..

One thing (for me) that might be an issue, at the rear bottom of my hull, is a "FLAT" that extends maybe a foot forward before it turns back into a "V".

I don't know if that would make a difference with TURBULENCE in that area (which is about the only place I can put it)...

I've read to test the area, put the transducer where you want it, weigh it down (I have soft scuba diving weight bags-which would work perfectly) then put enough water in the hull to just cover it...

Also, the only flat area INSIDE the hull has the bilge pump/float attached..

There's room forward of that but is NOT smooth. Not much room (or how thick) to smooth down the fiberglass.

Would the epoxy take up the lack of smoothness inside the hull(of course all bubbles worked out) and allow the transducer to work correctly?


.

[pstephens46]

I like my temp gauge so it's on transom.

Through hull would seem to be best. I have seen some botched jobs. Either leaking or turbulence issues.

Are there any "modular" systems available yet? I might not want to replace my 20" monitor or transducer. I just want the new and improved "guts".

Don't get me started on Lowrance.....

[fairdeal]

the prior owner of my boat had (cleverly, I thought)
simply laid an ordinary Garmin "transom mount" transducer in the aft bilge.

Purely for depth - it was remarkably accurate, despite shooting through almost 3/4" fiberglass.




I wanted better "fish finding" - plus the fancy "side scan" - so I installed an in-hull transducer.

[boscoe99]

Had a Lowrance X15 many many years ago. Paper graph fishfinder. Aluminum V hull with many many rivets on the bottom. Transom mount transducer did not work so well due to aeration from the rivets I suppose. Epoxied the transducer to the bottom of the boat so that it was a "shoot through" configuration. Worked well in water up to about 80 feet depth. Hull was maybe 1/8th inch aluminum I suppose.

[99yam40]

I did not realize they would shoot thru a metal hull.
if the rivets were a problem with it hanging on the transom,you would think they would still be a problem shooting thru also as they would still cause the turbulance.

seems the glass hulls I helped friends work on were several inches thick.
No wonder they do not put flotation in those large boats. so heavy you could not get enough flotation in the hulls to float it

[panasonic]

Mine is currently on the transom but would definitely prefer having it inside..

One thing (for me) that might be an issue, at the rear bottom of my hull, is a "FLAT" that extends maybe a foot forward before it turns back into a "V".

I don't know if that would make a difference with TURBULENCE in that area (which is about the only place I can put it)...

I've read to test the area, put the transducer where you want it, weigh it down (I have soft scuba diving weight bags-which would work perfectly) then put enough water in the hull to just cover it...

Also, the only flat area INSIDE the hull has the bilge pump/float attached..

There's room forward of that but is NOT smooth. Not much room (or how thick) to smooth down the fiberglass.

Would the epoxy take up the lack of smoothness inside the hull(of course all bubbles worked out) and allow the transducer to work correctly?


.

As long you use Two part epoxy...slow cure and the fiber glass is good and clean ...acetone.

Put the transducer in a nice sized thick zip lock bag half filled with water and put it where you think it will be good.

[TownsendsFJR1300]

Great idea, thanks!

[oldmako69]

The pin-head who mounted mine (two of them) placed them about 1/2 inch to either side of the garboard drain. This placement makes plug removal a bit of a pain as there is very little room to swing a wrench. Fortunately its a solid transom with no wood because I'm sure that they would have done nothing to protect the core aside from a quarter dab of goo.

I guess that moving them an inch more outboard would compromise the accuracy depth reading.

I guess anyone with a pulse can rig a boat these days.