Hydrofoils: must have or silly accessory?

[blueblackstripedmarl]

Hi everyone, just after opinions here, having had several outboards, some with, some without hydrofoils - the last was a honda 90 with a permatrim, Ive now updated to a 115 yamaha 4 stroke but no hydrofoil. (yet)
I was thinking about adding it, but wouldnt the manufacturers design motors with a hydrofoil if it was necessary? are the claims true or false? looking forward to your advice
john

[peterbo3]

The foils can help some boats. Yamaha, Suzi, etc design a motor to put out a certain HP. What happens to it after sale is not their problem.
Some boats are underpowered or badly balanced & take forever to get up on the plane. Foils may help here. But foils can also cause handling problems when turning.
If the boat runs well & gets out of the hole quickly a foil may not be needed.

[toolman2810]

well that was educational

[toolman2810]

They definitely make it easier to step back in after a swim

[ozscott]

They look good...

They help many boats but hinder others. You dont know till you put it on. Overall top speed is usually a shade down if any of it is still in the water when flat out. I found it helped my heavy Vagabond, but then I took it off and went for Bennett Hydraulic trim tabs and the difference in control was very noticeable. Also the wings can prove dangerous in a following see when you want a more bow up attitude and the wing tends to do the opposite. I never had mine on in a big following see so I dont know first hand.

My old uncle when he was alive ran a V16 Haines with a 150 on the back in and out and around Magnetic. He wanted to be able to plane slower in big seas (he was quite mad) and his mechanic said that if he didnt want to got the expense of tabs, to use a wing...so he did and in the first big following see he nearly lost the boat from broaching (he was very experienced and really knew how to drive but said it was unmanageable with the wing) and he took it off ASAP and would never go back.

Cheers

[allabaster]

They definitely make it easier to step back in after a swim

I belive the ancient greeks came up with an invention called a ladder.
Some people even put these on boats the crazy cads.;D

[BM]

They look good...

Isn't it remarkable how we all perceive things differently!!!

I think that foils look like a bandaid add on that destroys the design intentions of the engine.

Cheers

[Smithy]

My thoughts from a similar topic only a day or so ago.

http://www.ausfish.com.au/vforum/showthread.php?t=125290

[blueblackstripedmarl]

thanks for everyones responses, Still not sure I guess its always different boats different results but to me the trim issue seems the main benefit going from permatrim to without. Ive noticed its harder to get the nose down inititally but then once planing everything is fine. The thing is that the extra drag and handling vices could be canceling out any benefits. Im tending to think if its not broke dont fix it, but still not sure. these things came on the market and lots of punters just went out and put them on. Ive never heard a thing about what the manufacturers say, the outboard mechanics I know seem fairly ambivalent about them- any die hard hydrofoil supporters out there?

[Luc]

I run a permatrim on my 4M tinny and would not consider removing it.

Gets on the plane faster, stays on the plane at lower speed and give me great trim control.

I haven't noticed any unexpected handling vices.

Luc

[charleville]

A bloke who used to work in the Australian head office of Mercury once told me that years ago Mercury sold them as an accessory but took them off the market after a couple of boats flipped in the USA doing tight turns.

[manchild]

IMo if you need them ,then something wrong with your setup.Engine height,weight,hp.Agree with the bandaid comment.
cheers
George

[trueblue]

mine is a complete pig without the foil...

[black runner]

I had a Merc20 Blue band on a 4M Tinnie. Did ok with 2 on board but any more and it was hard to keep on the plane at lower rpm. It was 20 years old so I wacked on a set of Lasers (less than $40). Made a huge difference at lower speeds and seemed to run cleaner at the rear throughout the range. No handling probs whatsoever.

Cheers

[Horse]

I fitted a foil and it improved the boat greatly. My main issue was lack of nose down trim. The foil provided this and has made the boat much stiffer and better riding. Top speed has not been reduced and she jumps out of the hole very flat and easily.
Mind you this is on a 70's designed Oceaneer hull and the new Yammie just did not seem able to trim it correctly. I would be suprised if they were needed on a newer hull

[squizzytaylor]

In my humble opinion, yes they probably are a "band-aid" solution in most cases, However not all boats are created equal and certain types of boats (i.e. 4ish metre tinnies, tiller steered with 25-40hp engines) are notoriously stern heavy and the addition of a permatrim (the only brand worth even considering imho) can make them far more handleable and remove low-intermediate bow rise which can also be bloody dangerous.
There are other options however which dont carry the strange handling characteristics of foils i.e. Smart-tabs (google it) and also remove the bow rise.
Having said that, if the boat is good the way it is, why mess with it.

Geoff