Fitting Raymarine Through-Hull Transducers to Fairline Targa 40

[danieleither]

I've recently got into fishing from my Targa 40 and would like to fit through-hull transducers to add fish-finding and sonar functionality to my Axiom Pro S setup.

The transducers come in various flavours for different hull deadrise, the options are:

0 degrees
12 degrees
20 degrees

Which would be the correct option for my boat, and why?

 

[Portofino]

They fitted transducers on my boat on purpose built flat spots along the keel in the midline .Size of the palm of your hand .
That way they are effectively on a flat bottom.The inside is glassed flat too to ease fitments like the ring screw .

They did not just drill one side of the V .

 

[danieleither]

They fitted transducers on my boat on purpose built flat spots along the keel in the midline .Size of the palm of your hand .
That way they are effectively on a flat bottom.The inside is glassed flat too to ease fitments like the ring screw .

They did not just drill one side of the V .

Ahh, I didn't know the Targa 40 has flat spots on the keel, however there will be 2 x transducers (port and starboard) so not sure the flat spot would help (unless I don't actually need two)? I assumed 2 x transducers gives more detailed imagery but I may be wrong...

 

[petem]

Ahh, I didn't know the Targa 40 has flat spots on the keel, however there will be 2 x transducers (port and starboard) so not sure the flat spot would help (unless I don't actually need two)? I assumed 2 x transducers gives more detailed imagery but I may be wrong...

Portofino is talking about his Itama which is rather irrelevant.

 

[ST840]

Ahh, I didn't know the Targa 40 has flat spots on the keel, however there will be 2 x transducers (port and starboard) so not sure the flat spot would help (unless I don't actually need two)? I assumed 2 x transducers gives more detailed imagery but I may be wrong...

It depends on what type of fishing you tend to do? If your wrecking than panoptix and front/back and side scanning is good. I use all Garmin stuff but I'm sure Raymarine will do an equivalent to the V12 transome mount. And for traditional down scan and clear scan I use a Garmin GT41, again transome mount.
Why do you need through hull??
They are more expensive and imho a liability if not fitted correctly.
Transome mount is just as good if located correctly.
Id give your local dealer (electronics) a call and discuss.

 

[Portofino]

They fitted transducers on my boat on purpose built flat spots along the keel in the midline .Size of the palm of your hand .
That way they are effectively on a flat bottom.The inside is glassed flat too to ease fitments like the ring screw .

They did not just drill one side of the V .

Portofino is talking about his Itama which is rather irrelevant.

Not really Pete .
He‘s gonna have to make a hole if he goes down the TRH route ,Generic really , they all do this stuff .

I never mentioned a marque specifically.Turn your FL dial down a few notches .

Just telling him how it’s done by professional builders , the TRH bit .
In fact as one can see there is a bit more to it .
Depending on which kit , he might want to hire the services of a glass up guy who will make a flat spot in the centreline and of course sort out the interior beef it up add a flat shelf to accept the interior fitting(s) .In an accessible place interior wise .So the zero degree transducer works optimally.

Rather than just let the fitter bung a hole in any place other than the flat centreline without any internal backing plate ( my beef up ) …..and run out of the yard after talking his money .Or dare I say it use self tappers on his FL - seen that before .

Only for the op to find the kits pretty useless because he inadvertently bought the wrong 20 degrees when it should have been say a 12 in a true Sod’s law way .Sods law and boats never far away from each other .

Remember it’s been on the hard for this , so he’s 8 uggered until next year .

Further more at resale some nit picky buyers surveyor picking up on not so professional fitting of this aftermarket transducer.

Details Pete details and quality . I am happy to share and justify why .
Take a horse to water etc etc .

Arh hang on folks .It’just occurred to me Fairlines of that genre have cored and hulls with a grid system of some cell materials and a internal liner or skin inside ,
So wait a min !
I assumed they just had the trad solid glass hulls , by which if you opened up hatches in the saloon or went into the ER you could see the cross members , ribs etc used to support the outer skin / hull .Thus pic a spot to drill , through solid fibre glass .
Be it laterally or indeed in the centreline ( with a flat spot made externally + beefed up internally ) .

But no its a double skin boat with a thinner external skin , a middle grid to support the shin and an internal liner glued in to reinforce .
So drilling this could be problematic because…..
You don’t know where the grid pieces are under the internal liner .
Do you locate them ?
Will you 1/2 chop one ?
Do you go through a grid section - erh 80 -129 mm dia hole?
Do you go through only the twin skins - the internal liner - air gap - to outer thin skin ?
Hows the tightening ring internally gonna work against a inner liner ?

Good job I raised the build spectre ……see now Pete the relevance .

Not to sure it’s a good idea to go gun hoe with a drill and a liner boat .

Having gone through this see ST840 s post = hang on off the transom , put it away when not fishing = simples .

 

[stelican]

Porto.
I don't know who feeds you info but the FL40 has a traditional stringer system (to Lloyds scantlings) which the lining is bonded to.
Suggest you have a look at one before making that type of statement in future.
The Italian Gobbi /Atlantis range has all the insurmountables that you quoted, perhaps you muddled the two

 

[petem]

@Portofino I don't know how many times I've told you, Fairlines of that era don't have cored hulls.

 

[Portofino]

What erroneous with my post guys .
Double skin , A outer hull with a lining with quote myself “ something glued in between , a cell or grid .

What do you guys PeteM and stelican mean ?

Its still problematic as I outlined fitting a after market DIY ish through the hull fitting .
3 layer s
1-inner lining .
2-Either a piece of grid , part of grid or air gap .
3- Outer skin / hull .


The middle bit is called a what ? Grid , sandwich , core arn‘t they interchangeable in terms of description ? ?

What’s your issue guys with the nomenclature ?

The risk of ball’s ing it up is still there swinging a 120mm core bora about .

 

[stelican]

What erroneous with my post guys .
Double skin , A outer hull with a lining with quote myself “ something glued in between , a cell or grid .

What do you guys PeteM and stelican mean ?

Its still problematic as I outlined fitting a after market DIY ish through the hull fitting .
3 layer s
1-inner lining .
2-Either a piece of grid , part of grid or air gap .
3- Outer skin / hull .


The middle bit is called a what ? Grid , sandwich , core arn‘t they interchangeable in terms of description ? ?

What’s your issue guys with the nomenclature ?

The risk of ball’s ing it up is still there swinging a 120mm core bora about .

Sorry you are completely wrong.
You need to ask a Fairline owner if you could have a look at his hull construction.

 

[Portofino]

Sorry you are completely wrong.
You need to ask a Fairline owner if you could have a look at his hull construction.

What’s the forum for ? Jump back in the pram

Fess up whats immediately under the “ liner “ your words from post # 7 and a term I am not disputing.

Hate for the op ( or his tech ) to pierce quote you again a “ traditional stringer “ by accident and weaken it drilling a hole say 80-120 mm through it .
Especially if it’s actually only say 70;mm wide .See the problem looking from the inside or outside for that matter .

My point about going for the hanging off the transom version of a fish finder stands with this type of build aftermarket.

 

[danieleither]

Transom mount is not suitable for outdrive boats, as the prop wash interferes (in fact blocks according to Raymarine) the sonar signal. Further, I'm looking for a more elegant solution than shoving a transducer in and out as and when I need it. It will be Hudson marine who supply and install, their reputation is good so I would hope they know what they're doing...

 

[stelican]

What’s the forum for ? Jump back in the pram

Fess up whats immediately under the “ liner “ your words from post # 7 and a term I am not disputing.

Hate for the op ( or his tech ) to pierce quote you again a “ traditional stringer “ by accident and weaken it drilling a hole say 80-120 mm through it .
Especially if it’s actually only say 70;mm wide .See the problem looking from the inside or outside for that matter .

My point about going for the hanging off the transom version of a fish finder stands with this type of build aftermarket.

Well I don't find it necessary to reply to Blurb on a forum. If you want the answer go and look in the bilges of a Fairline as you are completely misleading the OP

 

[Portofino]

Transom mount is not suitable for outdrive boats, as the prop wash interferes (in fact blocks according to Raymarine) the sonar signal. Further, I'm looking for a more elegant solution than shoving a transducer in and out as and when I need it. It will be Hudson marine who supply and install, their reputation is good so I would hope they know what they're doing...

Good idea they will have glass men to make good much like fitting bow thrusters.

 

[stelican]

Transom mount is not suitable for outdrive boats, as the prop wash interferes (in fact blocks according to Raymarine) the sonar signal. Further, I'm looking for a more elegant solution than shoving a transducer in and out as and when I need it. It will be Hudson marine who supply and install, their reputation is good so I would hope they know what they're doing...

Hudson have a good reputation this is everyday work for them. Discount naysayers on here as they are not aware of the way a Fairline hull is constructed.

 

[danieleither]

Even if don't get the answer to my question, it's entertaining watching you guys bicker...!

 

[Portofino]

Well I don't find it necessary to reply to Blurb on a forum. If you want the answer go and look in the bilges of a Fairline as you are completely misleading the OP

How ?
Surly I will only see the inner liner .
I,am asking you to correct my nomenclature.
I am asking what’s immediately under the liner .
In between the two skins .Namely the exterior hull , you know bit in contact with the water it floats in and his inner glued liner .

Is it sold , a grid , air ……what exactly is hidden under that liner .

 

[danieleither]

I am by no means an expert, but if it helps, when opening hatches (in engine bay, saloon, cabins etc) I can see what appears to be the inside of the bottom of the hull. There are various seacocks for A/C, generator cooling etc and looking at the way they are mounted would suggest there is no 'inner skin' and that I am looking at the very bottom of the hull. These are just observations as a layperson... I assume they would identify the correct place / places for the transducers from inside the boat first, drilling a small pilot hole from the inside then drilling the full size from outside in? Or even the full size hole from inside if space permits?

 

[stelican]

I am by no means an expert, but if it helps, when opening hatches (in engine bay, saloon, cabins etc) I can see what appears to be the inside of the bottom of the hull. There are various seacocks for A/C, generator cooling etc and looking at the way they are mounted would suggest there is no 'inner skin' and that I am looking at the very bottom of the hull. These are just observations as a layperson... I assume they would identify the correct place / places for the transducers from inside the boat first, drilling a small pilot hole from the inside then drilling the full size from outside in? Or even the full size hole from inside if space permits?

You are correct, That is the hull laminate painted over with a white gel coat wash where visible.
Its everyday work for them.

 

[Portofino]

You are correct, That is the hull laminate painted over with a white gel coat wash where visible.
Its everyday work for them.

Now what are you sweeping under the carpet ?
Nope it’s a liner , its not the inside of the outer skin painted over.

Fairline video

Another one ( stelican ) I am off there xmas list .