Your experience with a hydrofoil (especially on a 228)?

[luckydude]

I stumbled on this: https://www.amazon.com/Marine-Sport-Hydrofoil-300-SE/dp/B003L8QS36 and the comments make it sound like you can stay on plane at slower speeds. Which makes sense to me because when my engine is trimmed all the way forward it is not straight up and down, it is slightly tilted forward. So it seems like it would work but does anyone have any first hand experience?

 

[SkunkBoat]

not a fan. tried one on a 40hp on a tin boat. killed speed and power. Took it off.

Don't do it.

 

[WiltonGrady232]

I had one on a 22ft cuddy cabin boat years ago. It had a v8 sterndrive. It was very helpful. I didn't have trim tabs on that boat, and the hydrofoil gave me the ability to really trim the boat. It improved my planing time and allowed me to stay on plane at a lower speed.

 

[glacierbaze]

I have used in the past, but I think that you get better results from trim tabs, and all my boats have had them for the past 20 years. Never used both on the same boat. I did swithch from a fin to trim tabs on a 19 foot Four Winns, and that was my last fin.
I wouldn't trust one that is advertised as one size fits all, from 35 to 300HP. The favorite these days, by far, seems to be Permatrim. I never understood how something mounted on the anti-vent plate, which should be on top of the water at cruise, is going to help anything beyond hole shot.

 

[Ryhlick]

You may have already tried it, but what about a 4 blade prop? I put a powertech16 pitch prop on my yamaha 225 and the ability to stay on a plane at slow speeds is fantastic. With out the boat being loaded too heavy, I can keep her planing between 14-16 using the throttle. Just a thought, there are trade offs for everything.

 

[family affair]

Read the Permatrim FAQ page to understand what they do. The product has it's applications, but I don't think it is a good idea on a bracketed boat. The foil needs to stay on top of the water to net the claimed performance. Hulls with short running surfaces (older Grady's) and bracketed boats don't keep the prop buried as consistently. This means under a lot of circumstances, the foil will be under water hurting performance.

 

[luckydude]

You may have already tried it, but what about a 4 blade prop? I put a powertech16 pitch prop on my yamaha 225 and the ability to stay on a plane at slow speeds is fantastic. With out the boat being loaded too heavy, I can keep her planing between 14-16 using the throttle. Just a thought, there are trade offs for everything.

I have what Ken at Propgods said to buy, it made maybe 1/2 mile per hour stay on plane difference. That's not what I am looking for, my 228 is modern and heavy, it really wants to fall off plane around 20mph in my ocean, might be more like 19 in a really flat ocean. One of the comments in the amazon reviews said it made the boat stay on plane 5 mph slower. THAT is what I want. There are many days where I'm coming home and I can't do more than 16-18mph so I'm off plane and getting shit MPG. I'd love to be able to go those speeds and stay on plane.

 

[Mustang65fbk]

For less than $70 I say give it a shot to see if it even works and if it does, how much of a difference does it make? If it doesn't work or isn't to your liking then you can always return it. If you don't feel good about returning it then I'm sure you could likely sell it and make most of your money back. But again... for $70 it's not much to lose sleep over if it doesn't work and you can't return it. I wonder if using something like this would make you need to change up your prop size/pitch again?

 

[PointedRose]

One of the comments in the amazon reviews said it made the boat stay on plane 5 mph slower.

I personally find it hard to imagine 5mph lower plane happening, I if I were you, I would want someone with a similarly sized GW to back up the claim (which I know is what you’re trying to do here). I do see these features on many more boats out west than I did in cape cod, so maybe there is some practical use cases, but just makes me wonder if they were so effective, the OB manufacturers would have designed differently a long time ago. I just don’t like the idea of drilling into the lower unit and think adding bolts would add drag too. Maybe I’m way off though.

 

[PointedRose]

for $70 it's not much to lose sleep over if it doesn't work

but then you’ve got 4 bolt holes in your lower unit

 

[Mustang65fbk]

but then you’ve got 4 bolt holes in your lower unit

On the fin yes... which isn't structural. Besides looking a little funky having 4 empty bolt holes there with nothing in them, I can't see there being any other issues. If one really wanted to they could always buy a replacement lower unit if the 4 open bolt holes really bothered them that much. Or buy a used one and try this hydrofoil on it so that you aren't drilling holes into your own. There are a few different possibilities, just depends on what you want to do and how much you want to spend.

 

[DennisG01]

Generally, I'm not a fan of them in the sense that it really depends on the boat. I think they make more of a difference on smaller, lighter boats (physics, based on the amount of upward pounds of "lift" they provide). Trim tabs are wonderful and beat out a fin any day of the week for multiple reasons... except cost. But there are Smart Tabs that are less expensive and are still better than a fin.

HOWEVER... I think Lucky has found an even better solution... right, Lucky?

 

[mdscole]

I have what Ken at Propgods said to buy, it made maybe 1/2 mile per hour stay on plane difference. That's not what I am looking for, my 228 is modern and heavy, it really wants to fall off plane around 20mph in my ocean, might be more like 19 in a really flat ocean. One of the comments in the amazon reviews said it made the boat stay on plane 5 mph slower. THAT is what I want. There are many days where I'm coming home and I can't do more than 16-18mph so I'm off plane and getting shit MPG. I'd love to be able to go those speeds and stay on plane.

Hey LuckyDude! It's Mitch...
These do want to fall off plane at a relative high speed. My 248 is the same way. I can get down to about 18 mph with the trim tabs fully extended - but that's about it. Another consideration is to keep little fuel in the rear tank and mostly run off the front - that helps keep it on plane as well.

I have used the hydrofoil on a much smaller 17' runabout and wasn't impressed.

One of the higher stern lifting props out there is the Mercury Enertia Eco prop. It's a considerable investment, but take a look at some of the testing reports online with that propeller. I have one under my desk - waiting for Mercury to deliver an engine. I won't be able to give you the results till April unfortunately (1 year lead time!)

 

[Halfhitch]

I agree Dennis. I think lucky probably chose the most expensive option there is for increased comfort in the chop.

 

[glacierbaze]

Largest boat I used one on was the 19 foot Four Winns cuddy, with an I/O. I got some very squirrely and unpredictable reactions, when laying it over at an angle on turns at speed. That was why I took it off, plus it did not cure my porpoising problem with that hull, which trim tabs did. I would be very reluctant to have one on a bracketed outboard.
If you do try a Permatrim, I would suggest the undermount, which spreads the pressure over the surface area of the AV fin, where the top mount puts all the pressure on four bolt holes.

 

[DennisG01]

I agree Dennis. I think lucky probably chose the most expensive option there is for increased comfort in the chop.

Yeah, no doubt!

 

[Doc Stressor]

I'm late to the party, but I want to add that I tried fins on 4 different boats over the years. 3 of the engines ended up with holes in the anti-ventilation plates plugged with 5200. The discussion pretty much covers the important points. They really only work for light hulls that don't displace much water. Engine height is very important. If the fin drags under the water, performance and fuel economy take a hit. Without an adjustable jack plate, it is very difficult to get things set up right. I was able to decrease the planning speed on my old pre-SV2 Seafarer by a couple of mph, but if I trimmed the motor in to reduce pounding at higher speeds, the increased drag hurt performance too much. It was not a good tradeoff.

The one boat where a fin made a difference was a 2004 Key West 186. The boat was designed for a 2-stroke engine but this one had a heavier F150 and porpoised like crazy. I could stop this with the trim tabs, but the performance was unacceptable. On the advice of a mechanic at my marina who was well acquainted with the problem, I tried an aluminum fin from Bob's Machine Shop. He said that was the only one that worked. It solved the problem perfectly. It is a different kind of fin that is designed to minimize drag and extends mostly behind the anti-ventilation plate. Interestingly, Key West solved the problem in 2006 by reducing the size of the fuel tank from 65 to 40 gallons and moving the tank forward in the hull.

Bob's calls their fin a Stabilize Plate. It is amazingly well-engineered like almost all of their stuff.

Stabilizer Plate

 

[luckydude]

Generally, I'm not a fan of them in the sense that it really depends on the boat. I think they make more of a difference on smaller, lighter boats (physics, based on the amount of upward pounds of "lift" they provide). Trim tabs are wonderful and beat out a fin any day of the week for multiple reasons... except cost. But there are Smart Tabs that are less expensive and are still better than a fin.

HOWEVER... I think Lucky has found an even better solution... right, Lucky?

Yeah but I'll still fish the 228 when the 300 isn't available (not here yet, bottom paint, electronics) so I'd like it to work as well as possible.
I'll mess around with the trim tabs more, I'm getting more used to them.

 

[DennisG01]

Yeah but I'll still fish the 228 when the 300 isn't available (not here yet, bottom paint, electronics) so I'd like it to work as well as possible.
I'll mess around with the trim tabs more, I'm getting more used to them.

Oh, well, heck - yeah, if you haven't been using your tabs, you're leaving an awful good tool in the toolbox unused. Super fast hole shot... holding plane at slow speeds... heck, with that size boat you can probably keep the boat level even at speeds LOWER than "on plane". They're really a great help. But to get proficient at them, it does mean that you have to... wait for it... go boating more often!

 

[luckydude]

Oh, well, heck - yeah, if you haven't been using your tabs, you're leaving an awful good tool in the toolbox unused. Super fast hole shot... holding plane at slow speeds... heck, with that size boat you can probably keep the boat level even at speeds LOWER than "on plane". They're really a great help. But to get proficient at them, it does mean that you have to... wait for it... go boating more often!

I've got about 1400 miles on the big engine in 17 months, don't know what's on the kicker. That's some boating

I've been trimming the engine forward to push the bow down and using the tabs to correct leaning to one side or the other. I can add a little more tab in on both sides and see what it does.