hydrofoil?
Submitted by MetroMako on Mon, 2012-08-06 17:37
gday i am wondering whether or not to put a hydrofoil on my boat.
have heard good things and bad things.
GOOD THINGS: fuel consumption up on the plane a bit better and levels out quicker.?
BADTHINGS:not as stable when anchored or just sitting there.?
is any of this true?.
cheers
katsy85
Posts: 209
Date Joined: 13/02/12
Is there a reason u want one,
Is there a reason u want one, like can't get on plane quick enough?
MetroMako
Posts: 245
Date Joined: 17/07/12
hydrofoil
jumps on the plane pretty good just wanna make the front go down a bit.
nev
Posts: 193
Date Joined: 04/02/09
Permatrim
are one of the better Foils. I fitted one to a 6 metre Ally and it was a major improvement. Got the stern up higher on the plane and helped stop a lot of pounding. It was worth the money. They will get the nose down for sure.. Cheers
Paul H
Posts: 2104
Date Joined: 18/01/07
You will get varying results
You will get varying results depending on the hull and type/size of foil. You mention wanting to keep the nose down> I assume you've tried trimming the motor right down. other option may be some adjustment on the motor mounting to get more trim down. I have one on my boat and it mostly works only downfall for me is when trolling it sometimes wants to jump up on the plane and take off when I don't want it to. Some of the bad things I've heard are they can be bad in following seas (gives following waves something to push the back of the boat up with which is when you don't want the front to dive down), but isn't a problem for me.
Youtube Channel - FishOnLine Productions
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carnarvonite
Posts: 8673
Date Joined: 24/07/07
Last resort
IMO they are an absolute last resort to try to fix a bad handling boat.
They can make your boat very unstable in a following sea and cause it to broach because of the lift they give to the stern of the boat. It doesn't bring your nose down but lifts the back up and thats what causes the trouble.
Try shifting weight / fuel tanks / batteries, passengers etc forward. Take a look at the outboard and see if the pin is in preventing it from going down further or if there is a wedge between it and the transom that can be removed or lessened.
MetroMako
Posts: 245
Date Joined: 17/07/12
hydrofoil
its actually real nice on the plane,when moving fast but when i enter the river speed limits etc
rises a fair bit higher with motor trimmed as far as she can .
also have the weight sorted out,and do you have to drill holes to attach the hydrfoil?
cheerz for the info.
carnarvonite
Posts: 8673
Date Joined: 24/07/07
Plane
If the boat is fine on the plane but sticks the nose up when you slow down then you shouldn't add anything to it. If you drop the revs a bit more instead of staying in the range that just under planing speed the nose will come down and there won't be more than a knot difference in your speed and a huge reduction in fuel used to push the big bow wave.
carnarvonite
Posts: 8673
Date Joined: 24/07/07
Plane
If the boat is fine on the plane but sticks the nose up when you slow down then you shouldn't add anything to it. If you drop the revs a bit more instead of staying in the range that just under planing speed the nose will come down and there won't be more than a knot difference in your speed and a huge reduction in fuel used to push the big bow wave.
Dizzy
Posts: 753
Date Joined: 21/02/11
Trim tabs are a far better
Trim tabs are a far better option than a foil, and are only in the water when you want them there - so won't provide any unwanted handling characteristics.
They also give the benefit of being able to level the boat laterally in a cross-wind or when the load's not quite balanced.
If your tub is already good at speed, then a foil is only going to add more drag and (as Carnarvonite says) potentially cause issues in a following sea.
Tabs are obviously a more expensive option, but Hayways had some Bennets going for a very good price in the FS section.
If your boat already gets on the plane ok and trims nicely at speed then you really need to consider whether you need anything.
But I know exactly where you're coming from regarding River / canal speed limits - a little stern lift can make things much more pleasant, especially if everyone's sitting up the back.
nico
Posts: 226
Date Joined: 17/08/10
Props can sort bow lift too
Props can sort bow lift too some give more lift in the stern just by adding extra cup in the blades this topic has been raised several times boat set up and weight distribution all plays a part hydrofoils are a definate last resort .
In Mocean
fisho-ron
Posts: 2539
Date Joined: 26/09/09
i have one on my southwind
i have one on my southwind sf655 with 200etec its a se300,
i have tried my boat with it on and off and for me it was 10 times better on, no probs in a folowing sea at all, actually handeled better, just trim it out more to suit, some boat designs were bad in following seas out of the mould.
i also seen a fuel saving but that could be due to 2 differant days for testing? very minamal anyway
there was no differant at rest that i could note.
the only thing that change for the worse, was at really tight conering while taking off on the power it cavitates a bit, i dont turn as sharp now and rarely happens.
1 other problem, if you dont have a boarding ladder is people tend to stand on it to get into the boat, i have a ladder and they still stand on it.
worth a shot mate and if its makes it worse then take it back off.
cheers