Hydrofoil for my boat

[Bull]

I am thinking of putting a hydrofoil on my leg. The leg is a seacore bravo2 and spins a 19 inch prop. The main reason for this is to get the boat to plane at a lower speed. I would like to hear some opinions on brands and how they perform.
Cheers Brett

[Blackened]

G'day

Permatrim. Why? It increases the lateral length of the anti ventilation plate, rendering it more useful. They're also nice and skinny profile to help with the reduction in drag etc.

Dave

[Chimo]

Have a mate who tried it on his leg and he took it off soon after. He gets a better result with his Lenco trim tabs that he has since fitted. With a leg its pretty hard to lift the motor ? so the foil ends up too low and makes lots of drag at any speed above really slow.

As you know for a foil and motor to be at the right height you need to be able to slide your hand between the surface of the water and the bottom of the foil when at speed and the motors trimmed out for fast running. (I know you wont actually try this as your arms not long enough and there is a prop to think about but it gives you the idea)

Cheers
Chimo

PS As Dave said Permatrim would be the only one to try if you don't have or don't want tabs.

[Horse]

Brett, I agree the permatrim would suit best for your boat. I think the others are going to be set too low due to the fixed depth of your cav plate and create too much drag. I'm pretty sure it will hold the aft end higher so you won't bog down as much

[2IC]

Mate if you got a slimmer crew this would not be an issue LOL

[Muddy Toes]

Could the 19 inch prop not be the issue?

[WalrusLike]

I lifted my motor another notch recently and so far it seems better. More lively response and easier to keep on plane at lower speed.

Early days yet though. Maybe ensure you motor has cav plate at surface or out when on plane before trying the foil?


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[thelump]

4 blade might lift the backside up a bit Brett.

[Smithy]

LZ Lazilas. $49 from BIAS. Cheapest and best around IMHO. Not happy with it, you have only done $49 and got 4 holes in your cav plate.

[johncar]

I too think you would want to make sure that your cav plate is clear of the water at your regular cruising speed making the foil also clear so that as you slow down the foil will start to do it job plus the leg will have to be kicked in a bit to make it work best. I just wouldn't want to be dragging it through the water all the time if your leg is a bit low.
But as Smithy said it doesn't cost a lot to try it and the spare holes can easily be filled.
Trim tabs if the cost doesn't worry you will give you more control all round.
Testing my tabs this week though I was only able to gain a couple of kts slower speed in a 5 metre plate ally boat with the tabs down vs fully up so it wasn't dramatic but the boat will plane along at 12 kts all day no worries.
Had a HH 680 years ago that was bum heavy and didn't like to go slow at all and I had tabs plus a Stingray foil and needed them both at times in crook conditions, but they did work and the foil was well clear of the the water at normal cruise speed.

[murf]

have you not got tabs Bull?

if not why not?

I tried the Permatrim on my boat with some success but the negative characteristics seen me remove it quick smart. I believe the Permatrim to be the last resort if you are going to be out in rough weather and big seas at all. Ask the Lump what my boat was doing in a following sea with the Permatrim on haha you have to be spot on with trim of motor /leg or it turns into a rudder and puts you into a power turn when surfing down the face of a big swell if trimmed out :o never trimmed it in too far in a following sea but that would be scarier I recon.

and yes sit your deckies on the bow rail :)

cheers Murf

[Bull]

Thanks for the replies Gents.
I'm pretty sure the cav plate is clear of the water when the boat is on the plane. Stingray do a foil that clamps onto the cav plate with no need for holes. But the last thing I want is the thing coming off and smashing the prop. Has anyone tried one of these.

[Noelm]

Lots of mention about raising the motor up a bit, not a real easy job with a stern drive, (Bravo 2) where it is now, is where it's going to stay! I guess like all these things, your only option is to "pay and play" it might be OK, might be a waste of time and money, it's your choice though.

[WalrusLike]

Lots of mention about raising the motor up a bit, not a real easy job with a stern drive, (Bravo 2) where it is now, is where it's going to stay! I guess like all these things, your only option is to "pay and play" it might be OK, might be a waste of time and money, it's your choice though.

Oops. :)


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[thelump]

have you not got tabs Bull?

if not why not?

I tried the Permatrim on my boat with some success but the negative characteristics seen me remove it quick smart. I believe the Permatrim to be the last resort if you are going to be out in rough weather and big seas at all. Ask the Lump what my boat was doing in a following sea with the Permatrim on haha you have to be spot on with trim of motor /leg or it turns into a rudder and puts you into a power turn when surfing down the face of a big swell if trimmed out :o never trimmed it in too far in a following sea but that would be scarier I recon.

and yes sit your deckies on the bow rail :)

cheers Murf

Yep scared the bejeezuz out of me!!! And I was just watching it from my boat!:)

[bigjimg]

Thanks for the replies Gents.
I'm pretty sure the cav plate is clear of the water when the boat is on the plane. Stingray do a foil that clamps onto the cav plate with no need for holes. But the last thing I want is the thing coming off and smashing the prop. Has anyone tried one of these.
Bull
I have one of the Stingray clamp on style foils.It does what I needed it to do and that was to keep the bow down when pulling the little ones on the tube.It also helps greatly when punching into a short chop on the bay at low speeds.I can plane easily at 10 knots with a level attitude.
For me it was money well spent and took me 15 minutes to install of which 8 of those minutes were spent extracting it from the bloody packaging. Jim

[Jarrah Jack]

Ask the Lump what my boat was doing in a following sea with the Permatrim

cheers Murf

Probably depended on where he was sitting....

[bobbyb]

mate go the 4 blader, Will help lift the bum....

i just so happen i have a solas 17p for sale if interested.

[stue2]

Have a mate who tried it on his leg and he took it off soon after. He gets a better result with his Lenco trim tabs that he has since fitted. With a leg its pretty hard to lift the motor ? so the foil ends up too low and makes lots of drag at any speed above really slow.

As you know for a foil and motor to be at the right height you need to be able to slide your hand between the surface of the water and the bottom of the foil when at speed and the motors trimmed out for fast running. (I know you wont actually try this as your arms not long enough and there is a prop to think about but it gives you the idea)

Cheers
Chimo



PS As Dave said Permatrim would be the only one to try if you don't have or don't want tabs.

that right Chimo....;D;D;D;D....

[bigjimg]

The Stingray XR111 is what i have fitted. Jim
92289

[johncar]

have you not got tabs Bull?

if not why not?

I tried the Permatrim on my boat with some success but the negative characteristics seen me remove it quick smart. I believe the Permatrim to be the last resort if you are going to be out in rough weather and big seas at all. Ask the Lump what my boat was doing in a following sea with the Permatrim on haha you have to be spot on with trim of motor /leg or it turns into a rudder and puts you into a power turn when surfing down the face of a big swell if trimmed out :o never trimmed it in too far in a following sea but that would be scarier I recon.

and yes sit your deckies on the bow rail :)

cheers Murf

I also had some nasty little things happen in the HH 680 running downhill in shorther steep swells. Can't say for sure that the foil contributed but quite possible, Also thinking back to an old VMR boat with twin outboards and foils on both also did some scary things in the same sea so it may be a downside. Depends on your boat and type of use, the things I mentioned above happened mostly at night when a bit harder to pick the sea conditions.
I would look at it as a last resort and try all the things like weight distribution and tabs first even if just fixed ones.

[mal555]

I also had some nasty little things happen in the HH 680 running downhill in shorther steep swells. Can't say for sure that the foil contributed but quite possible, Also thinking back to an old VMR boat with twin outboards and foils on both also did some scary things in the same sea so it may be a downside. Depends on your boat and type of use, the things I mentioned above happened mostly at night when a bit harder to pick the sea conditions.
I would look at it as a last resort and try all the things like weight distribution and tabs first even if just fixed ones.

The Hydra-foil will always put your bow down slightly, which of course will greatly assist hole-shot, slow planing and sloppy head sea conditions, but you do need to be quick on the slight leg up-trim when turning down sea, along with constant tweeking adjustments and a steady cruise speed or they can create a bow-steer effect.

IMO the Stingray is the best foil choice for larger (seven to eight metre), sterndrive fitted boats, along with transom mounted trim tabs.
They also assist high, narrow, deep V boats like the seven metre Whittley Cruisemaster with lateral stability (laying over on a chine just after reaching planing speed), instead of constantly working the trim tabs to stay level.

[U4REEL]

I installed foils on my Kc 5.2 hoping to get on the plane quicker with the little 60's.. First outing was nice and calm and I thought they were mint, second outing was a bit sloppy and the boat turned into a wailing banshee that wanted to kill me! Now my outboards look like a pin cushion :( agree with the other guys absolute last resort