What is the long thing attached to the hull?

[Benthic2]

Can anyone identify the long skinny thing attached to the hull ? Thanks. There's a few more pictures here:
https://www.yachtworld.com/yacht/1994-duffy-hardtop-9142104/

 

[Benthic2]

Sorry guys...picture posting difficulties......

 

[mvweebles]

EDIT - removed pics as OP managed to crack the TF code

No idea what the strake is. Too shallow for roll chock. Not a ground strap for electronics as it doesn't have that type of equipment (eg SSB). Maybe some sort of lightening protection? (EDIT: Agree these grounding options should not be painted). Maybe some sort of a bunk for trailering?

Will be interested to hear feedback from others.

Cute boat.

Peter

 

[Benthic2]

I was thinking that if it was for grounding or lightning it wouldn't be painted, but I really have no idea.

Thanks for the help with the pictures mvweebles

 

[RedRascal]

Very interesting, I'll say it's an appendage intended to create turbulence to reduce fiction on the back half of the hull. More speed and less fuel burn on plane???? Kinda of like the go fast boats that introduce air under the hull to increase performance.

Curious if someone actually knows what it's for.

 

[PierreR]

Possible keel cooler

 

[twistedtree]

Possible keel cooler

I was wondering the same thing, though I can't saw it particularly looks like one I've seen before.

 

[mvweebles]

I ruled out keel cooler because it's not dry-exhaust. I suppose someone could keel-cool instead of a heat exchanger (I've seen it done once). But seems unlikely. The strake is also very far forward compared to the engine.

Peter

 

[psneeld]

I agree that it doesn't look like/big enough to be a keel cooler.

But I have run a boat that was keel cooled but still had wet exhausts.

It was a crew boat using V channel welded to the bottom. They looked like running strakes on the outside but were inter connected in the engine room and a salt water belt driven pump supplied water to the long, stern exhaust tubes.

There never seems to be absolutes in boating but I also admit keel cooling and dry exhausts aren't common. This case may have been low profile boat without exhaust becoming a problem on the aft work deck so it had the exhausts exit the transom. Could also be practical on boats that don't want to run hot exhaust through an occupied space.

 

[PierreR]

In the listing, this boat is a 26' Duffy and lists a new tandem cooler installed with engine work in 2021.

 

[twistedtree]

In the listing, this boat is a 26' Duffy and lists a new tandem cooler installed with engine work in 2021.

That might explain it. Some newer engines have two cooling loops, one for engine cooling and a second for the aftercooler. It appears to be repowered, and perhaps a keel cooler was added for an aftercooler?

 

[High Wire]

Is there only one? Nothing matching on the port side? Just because there’s no SSB now doesn’t mean it’s not a leftover.

 

[Pete Meisinger]

Someone may have installed it to dampen the wave noise in the V berth.

pete

 

[Bob Cofer]

Looks a lot like a heat exchanger. Had one just like that for the refrigeration system on our big wooden boat.

 

[psneeld]

Looks a lot like a heat exchanger. Had one just like that for the refrigeration system on our big wooden boat.

Sounds like the listing explains it as a keel cooler. Baffled me as it is pretty long and narrow compared to the ones I have seen.... but I am sure haven't seen all of them.

Was yours stock retail or a custom one?

 

[PierreR]

Looks a lot like a heat exchanger. Had one just like that for the refrigeration system on our big wooden boat.

I was going to say that I have seen some cold plate refrigeration systems with that type of cooler but then I looked at the equipment listings.

 

[Bob Cofer]

Sounds like the listing explains it as a keel cooler. Baffled me as it is pretty long and narrow compared to the ones I have seen.... but I am sure haven't seen all of them.

Was yours stock retail or a custom one?

Ours was custom.

 

[Benthic2]

Thanks for all the feedback guys.

 

[DennisB1]

I have a similar tubing set on my GB49 classic for cooling the refrigerant for my freezer and galley refrigerator. Its about 8 ft long and doubles back for a total of 16 ft of tubing.

Check you refrigeration system. It does improve performance especially if the compressor is located in a hot engine compartment.

 

[Pascall]

It looks like a reinforcement in the polyester to which a bilge keel can be applied.
The English Michell MK have something similar, with some models a wooden bilge keel could be applied.

Greeting

Pascal.

 

[CaptTom]

My vote is still for some sort of keel cooler.

Need better pictures to be sure.

 

[sunchaser]

With an abnormally far forward rudder maybe an after thought tracking assist, if on both sides?

 

[Pascall]

My vote is still for some sort of keel cooler.

Need better pictures to be sure.

The surface seems much too small for keel cooling, especially since the power in this boat is.

Greeting

Pascal.

 

[DennisB1]

I agree that is too small for an engine keel cooler but it is the right size for cooling a the refrigerant from a freezer and fridge.

 

[Fish53]

I believe it’s a lifting strake, I’ve seen something similar on a couple of lobster boats. Keeps the bow up a little higher to keep the forefoot from digging in.

 

[chriscritchett]

I believe it’s a lifting strake, I’ve seen something similar on a couple of lobster boats. Keeps the bow up a little higher to keep the forefoot from digging in.

Almost certainly yes. It’s a stick, screwed and / or glued to the hull.

But I like how we on the internet love to overthink these things .

As engine power has evolved and semi-displacement hulls haven’t kept pace, all sorts of little tricks are done to them to assist when running a bit faster than they were originally intended. “Lifting rails” are very common on today’s lobster / downeast hulls to provide some of the lift & roll control you don’t get with round-bilge hulls.

My 30’ Sisu, ‘almost 12 knots but really 8-knot’ boat could really use a pair of them. And / or more hp.

 

[chriscritchett]

Now that I see that post, I really need to update my avatar..

 

[psneeld]

To be a lifting strake, wouldn't it need to be flatter and horizontal to the plane to lift?

 

[Fish53]

Certainly it could be a better design but it would work as presented. Like many V hulls a more triangular shape with a flat horizontal face to the waters surface wold be better.

 

[Fish53]

We're it a cooler it would be much more efficient if it were out of contact with the fiberglass hull. I have engine keel cooling on my boat and it's a cupronickel tube running about half an inch out from the hull between thru hull fittings.