Hydrofoils? Are they worth having?

 Hello Ladies and Gentlemen

Considering purchasing one of these https://www.gumtree.com.au/s-ad/osborne-park/boat-accessories-parts/hydrofoil-se-sport-300-black/1126572794?utm_source=transactional&utm_medium=email&utm_campaign=shared_ad


There are some big claims for such a simple device. Anyone have some opinions on them?


Dale's picture

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Date Joined: 13/09/05

Thu, 2018-04-26 19:44

 Might find some info here



"Just because you are a Character, Doesn't mean you have Character."

Mr Wolf



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Date Joined: 25/11/15

  Once you have it on you

Fri, 2018-04-27 10:56

  Once you have it on you will notice the difference if you take it off . My one is not bolted but held by grub screws and trim tap bolt. You can lend if near Riverton . 

hilko's picture

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Date Joined: 27/03/18

You've opened a can of worms - depends on boat, engine config

Sat, 2018-04-28 16:43

Everyone will have their own opinion.
It will work for some and not others.

I have a 7.2M Razerline Olympian Hardtop with a 300HP Yamaha outboard and hydraulic steering and QL Trim Tabs. (all of these have a bearing on whether you might/might not).

I love it.

I had another brand held on only with grub screws in prior trip but on first Exmouth trip it came off.... never to be seen again.

I have now the exact same foil as per your link fitted - directly bolted on.

Best to explain what my b4 and after situ was...

before: At speed with trim right up (say 50kmph behind Garden Island coming back in and going diagonally across following swell, I constantly felt uncomfortable with boat threatened to broach ie duck left or right - to the point I had to reduce speed and hang on to steering with both hands just in case....

after: I've lost a few KMs in speed - I'm guessing approx 4kms - who knows...
But the boat now seems to be a "bit more anchored" in the back and in similar conditions as above the boat wants to go straight on without me needing to hang onto to steering at all.
And peace of mind :)

Willy's picture

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Date Joined: 10/04/08


Fri, 2018-05-11 14:41

 Hello Gents

Thanks for the response, and Dale, thanks for the link.

Had a good read and am now convinced that a hydrofoil should be fitted to the boat



Posts: 10

Date Joined: 07/12/11

They are very helpfull and

Fri, 2018-05-11 15:11

They are very helpfull

and trim tabs if the boat is small enough make a difference also

carnarvonite's picture

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Date Joined: 24/07/07

Last resort

Sun, 2018-05-13 16:17

IMO they are an absolute last resort to try to fix the handling on a boat.

they give you lift on the stern of the boat and in a following sea it is exactly what you do not want as it is the major cause of broaching.
Sure they help you get on the plane earlier but is the cost worth it

still trying's picture

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Date Joined: 27/06/17

I started this thread last

Sun, 2018-05-13 17:43

I started this thread last time afew moths ago I still haven't put one on yet last time I went out I was quite happy with how the boat handled overall but it was a calm day and we were going pretty quick everywhere we went.


 rather be fishing

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Date Joined: 17/06/10

As has been mentioned

Fri, 2018-05-18 22:41

 Carrvonite has mentioned you should take due care when using them especialy if they are the type that are affixed to your boat stern,  and not the motor, which is what I have.

The type affixed to the motor can have their effect lessoned some what by adjusting the angle of the motor, and with a following sea this is most advisable IMO.

The hydrofoils that I have are not adjustable whilst on the water and when coming home with a following sea I have had 2 "exciting" experiances (near broaches) and this left me very dissapointed and worried about the use of them.

They certainly helped get the boat up onto plane at a lower speed than without having them but the down side was the lifting of the stern and destabalizing the boat whilst coming down the face of a swell even though I was riding the throtle all the while.

I solved this problem by altering the way the hydrofoil plates where attached to  the hull so that the hinge pin which held them to the hull could be removed on the water and thus render the plates ineffective. This removed the action of the plates entirely and I have no problems since making the mod.

The best hydrofoils to get are IMO electrically or hydrolically operated ones such as Bennet or similar, you can then make adjustments to suit all conditions and increase or decrease their effect at the touch of a button, I wish I had spent the extra dollars and got a set of bennets.

z00m's picture

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Date Joined: 10/05/14

Trim Tabs

Sat, 2018-05-19 07:45

Sounds like you have confused trim tabs with hydrofoils. Trim tabs are attached to the boat, hydrofouls are attached to the leg of the motor. 

Posts: 5056

Date Joined: 17/06/10

You are probably right

Sat, 2018-05-19 17:34

 But they both achieve the same thing don't they, that being to lift the stern of the boat and get you up on plane quicker

z00m's picture

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Date Joined: 10/05/14

Sort of

Sat, 2018-05-19 21:36

 Sort of yes but no. Hydrofoil angle changes with motor trim and can also reduce cavitation in some circumstances. By changing trim angle the hydrofoil keeps its relationship to the motor.

Fixed trim tabs as you mentioned always keep their relationship to the hull and not motor position. Fixed trim tabs can cause some fun in a following sea when they continue to force the bow down no matter what. With movable trim tabs you can overcome this by changing their angle.

hezzy's picture

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Date Joined: 27/11/09

have had hydrofoils on

Sat, 2018-05-19 08:35

have had hydrofoils on several motors on different boats, all bolted on , no grub screw

definitely get you up on the plane quicker and at lower revs, and will maintain that as well , cant say they increase fuel economy , but if you trim the outboard leg to the sea conditions you are in , following or not , they work very well and have never had issues with broaching

I would not hesitate to fit one if it was me ,

if you do fit one id suggest you take the boat out on a good day and do a bit of trial work with leg in different positions to feel how the boat handles compared to the before fitting



OFW 11

evil flourishes when good men do nothing


Jackfrost80's picture

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I took mine off after a few

Sat, 2018-05-19 10:48

I took mine off after a few times on the boat and I prefer the way the boat steering handles without the hydrofoil but my boat is arse heavy and it's much more enjoyable with the hydrofoil fitted as it helps push the hull through the chop rather than bouncing over it. I don't seem to get on the plane any faster but the transition out of the hole is much smoother i.e. I don't get that feeling like the boat is taking off if that makes sense.

Been meaning to experiment with some lead in the anchor well for weight to keep the bow down going through chop and removing the hydrofoil but haven't got around to it yet.


If catching wrasse is cool, consider me Miles Davis