Will a Hydrofoil Improve your Boats Performance?

[@micka63]

Thanks Paul for another informative video. I’ve been considering one for mine but was reluctant to drill into a new outboard. I didn’t realise there was a drill free version, I’ll be interested in some fuel economy figures if you could oblige in the future, as you said fuel is not getting any cheaper.keep the videos coming Thanks

[@weFishAU]

You're welcome. I know how you feel, I probably would not have tried it again if I had to drill holes.

[@punkit8804]

Thanks mate for your videos And a good voice ha h. My big benefits from h/f Is holeshot and lifting the transom at slow speed trolling for marlin.

[@weFishAU]

You're welcome. I didn't test the hole shot but it did stay on the plane at a lower speed as I eased off the throttle. I had to alter the amount of trim I use as well.

[@joelarrarte8486]

Nice vid Paul! Keep 'em coming!

[@weFishAU]

Thank you, will do!

[@stephenjeacocke1530]

They definitely work all boats iv fitted them to plane at lower speeds. Keeps nose from riseing when you start powering up carries loads better and cheaper running think I’ve mounted 10 of these to my boats and friends and there all happy as with same brand too

[@weFishAU]

That is good to know. As I mentioned, the only other boat I have fitted them to was my Hydrofield about 20 years ago and I didn't notice any real difference. If I ever own any other boats I will certainly be considering them.

[@dazl2954]

Works brillant as I have the SE Sports 400 on my Suzuki 40hp 4 stroke. I posted it on a forum and had some keyboard warrior's assume that it won't hold and would cause a heap of drag. Well they haven't come off (not even a sign that the bolts have got loose) and the drag is minimal as I am only doing less than 1knt less in speed.

[@weFishAU]

Given the measurements I got I am a little surprised to hear some people are getting a speed drop. Did you try it at different trim settings? I found I have to trim my engine differently to get the best performance.

[@dazl2954]

@@weFishAU yeah I definitely tried different trim settings as the 400 as it gave me more trim angle than without. I noticed that it helped stern lift on hole shot and kept the bow down, where as previously the bow would lift (that it was hard to see in front) and the stern would plough. Maybe I am experiencing the loss of speed due to the small motor 🤔

[@weFishAU]

Perhaps. It seems like the size of the boat matters so it seems reasonable that the size of the motor also counts. I was presently surprised with my results after my earlier experience with foils on my Hydrofield.

[@AquaMarine1000]

The device shown is for anti-cavitation. A true hydrofoil should look like the old style Stingray hydrofoil which has horizontal wings. A hydrofoil works on the same principle as an aeroplane wing in this case the water travels faster over the top creating lift. The cross section of these new so called hydrofoils have no foil shape so can't create lift. You'll never see a aeroplane with down curved wings like these hydrofoils. I tried one of the Sports hydrofoils with no effect. I then made a fibreglass copy of the old style Stingray with a few minor improvements, this now lifts the stern straight up out of the hole where the Sports struggled to get her up on plane. I have a once used Sports if anybody is interested. Cheers

[@weFishAU]

I guess it depends on the boat. Definitely works on mine. I think it does have an aerofoil shape but there are thousands of aerofoil sections and since water is a lot thicker than air it is unlikely that any of the aerofoils designed for planes would work as well in the water due to the vastly different Reynolds number of the medium. Angle of attack is likely to be more important than aerofoil section. The downturn will almost certainly have an effect on the tip vortices although finding out if the effect is good or bad would require testing in the water equivalent of a wind tunnel. With any luck someone will be interested in your spare one.

[@AquaMarine1000]

@@weFishAU Any improvement experienced is not due to any hydrofoil effect. Four accessories that are used to enhance performance, trim tabs, hydrofoils, anti-cavitation devices and stabilising fins. You may be experiencing the effect of one or a combination of three of the above but not the hydrofoil effect. Depending on the outboard trim you may be getting the effect of an extended trim tab and or increased planning surface as if the hull was extended which would give a better ride. Cheers

[@weFishAU]

A flat plate with a positive angle of attack will create lift so we might have to agreed to disagree on what constitutes a hydrofoil. It has had a positive effect on the performance and handling of my boat and that is all that really matters to me.

[@joelarrarte8486]

It is a complex issue when dealing with hydrodynamics for sure. Firstly however water is some 600 times denser than air so any aerofoil shape required to induce a lifting force is dramatically reduced in cross section. Secondly... B52, A7 corsair, Harrier jump jet or any of the heavy lifting planes (C5 Galaxy) to name a few have downward swept wings.

[@donninguyen5237]

Had a se400 but it fell off on a trip back from the fishing grounds... back to the ramp and gone lol

[@weFishAU]

Sorry to hear that. I gave mine a good tug and no chance of moving it. I will be checking the nuts from time to time to make sure they don't get loose. I expect the rubbers will compress a little bit over time.

[@ptkenterprise70]

I could not get on plane..... Today I put a hydrofoil on and SHAZAM! I ACHIEVED PLANE!!! I went from 10 mph max with my fat arse on the tiller to planing with 24 mph! Yaaaaaaay, me!

[@weFishAU]

It's amazing how much difference they make to some boats.

[@crikeymacca]

Be careful in a following sea! Not a fan. Prefer trim tabs and max HP

[@weFishAU]

It wasn't very rough but it was good coming back in over the bar the other day. Undoubtedly I will get to test it in more challenging conditions sooner or later.

[@sebastianfinocchiaro870]

I have the same one on my boat and It definitely gets up on the plane much quicker.

[@weFishAU]

When they do work for a particular boat it is a really noticeable difference.

[@senator62]

Hey Paul. Are you still running the hydro foil? Is it still working for you?

[@weFishAU]

Yes, I am. Still working a treat. I check it for tightness as part of the pre-launch inspection.

[@patrickamorosini2010]

My boat quicksilver activ 455 with honda 60CV hits a lot from the front, I hesite between flaps and a hydrofoil, what do you think? thank you for your answer

[@weFishAU]

Sorry for the late reply, I was out on the water for an overnighter. Hard to say. I had a 7.2m Hydrofield and I didn't think a hydrofoil made much difference. On the other hand, it has made a big improvement to my 6.2m Baysport. I think Zipwakes would probably be my pick if I had the money and space on my transom for them but the hydrofoil is way, way cheaper. If you get the same one I got then you don't need to drill holes and you could sell if second hand if it doesn't work for your boat. That was you would only be out a hundred bucks or so if it doesn't work as well as you would like.

[@patrickamorosini2010]

@@weFishAU Thank you very much for the answer. I looked at the zipwake, it looks great actually , dear, but very effective . Do you think that with zipwake the hydrofoil becomes useless?

[@weFishAU]

I can't see any reason to have both and I have never seen a boat with both. Undoubtedly the trim tabs and Zipwakes are more useful than a hydrofoil in that they can be differentially adjusted to compensate for list, albeit at a much higher cost. I had 4 transducers and underwater lights on my transom so any trim tabs were out of the question simply because there was no space left to fit them.

[@AnarchyEnsues]

I lose 1kt in calm with one on

[@weFishAU]

Can I ask what boat and engine combo you have? I played with my engine trim and got that correct (it was different to what I used without the foil) before I ran the tests.

[@AnarchyEnsues]

@@weFishAU 5.3m half cab fibreglass boat. 90hp 2 stroke. Total weight 1.2ton

[@weFishAU]

That is interesting. My previous boat was 4.6 with a 70hp 4 stroke. The fellow that bought it off me put a foil on it and said he got an improvement, although he didn't measure it. He also said he had to use different trim settings than he did without the foil.

[@AnarchyEnsues]

@@weFishAU mines not a scientific experiment. I trimmed up while speeding around the back of russle Island. I can get 32kts without and 31kts with. (Meaningless as I don't usually go wide open) And I don't know if it improves in the chop .

[@markcollins5026]

Man, looks like they only make your wallet lighter !

[@weFishAU]

On this boat they were a definite improvement in ride and economy. On the previous boat I fitted them to (7m Hydrofield) they didn't make much difference. So my conclusion is that it varies from boat to boat and you need to lighten your wallet to see if it is going to work for you.