Hydrofoil query again..............sorry.

[BIGMAX]

I have read a fair amount of the threads regarding hydrofoils, but am trying to establish just how successful these additions may be in saving fuel.
My neighbour has a 19ft Stingray with a 4.3 V6 Mercruiser which had a hydrofoil already fitted when he bought the boat. He has never removed it, thus does not yet know how the boat will perform without it. I am contemplating fitting a hydrofoil to my boat (19ft Seaswirl BR 4.3 V6 Volvo) in the hopes that I will save on fuel in the long run. The boat is primarily used for skiing, tubing, kneeboarding, etc, with a few long runs inbetween. I am somewhat concerned that the anti cav plate will have too much stress on it, thus causing it to crack or break. I could do with getting up on plane a little quicker to! Am I "chancing" it by installing a good quality hydrofoil?

 

[Drowned Rat]

Re: Hydrofoil query again..............sorry.

Hi BigMax. I believe the general concensus is that on a boat that size, the best you can expect is for it to have no effect whatsoever. The worst you can expect is decreased performance in the way of lower top end and on rare occasion, cav plate damage. I would never install one on that boat. Look at Smart Tabs. Inexpensive and very effective.

 

[BIGMAX]

Re: Hydrofoil query again..............sorry.

Thanks for the response, Drowned Rat. That pretty much seals it for me - that is to say - "NO hydrofoil for me".

 

[ziggy]

Re: Hydrofoil query again..............sorry.

"NO hydrofoil for me"

good idea........

and on rare occasion, cav plate damage.

i'll second that..........don't know if it's rare or not, but that's what happend to mine for having a hydrofoil on it.........

 

[45Auto]

Re: Hydrofoil query again..............sorry.

I had an 18' Bayliner bowrider with a 120 outboard. It was slow coming up on plane pulling skiers and tubes. Friend at work advised me that he had a 16' trihull with a 50 hp outboard when he was younger that wouldn't come up on plane until they put a hydrofoil on it. I put a $40 hydrofoil on my Bayliner and it made a HUGE difference. Rear end of the boat acted like it was on an elevator when you accelerated from a stop. Popped up on plane immiediatly pulling skiers and tubes. Top speed was always mid forties by speedo before and after (never checked it with a GPS). Never checked gas mileage either but it would seem that it would be at least equal since it came up on plane so much quicker. Had it on there from 2000 till I sold the boat this past summer. Never noticed any handling differences or problems.

Why not get your neighbor to try his boat with and without the hydrofoil? Should be just a matter of removing a couple of bolts. Then you would have a real reference point, very comparable to your boat, as to whether it worked or not.

Worst that will happen if you try one then took it off is that you would have 4 holes in your cavitation plate to seal up with a little paint. Too bad they don't make a "clamp on" version so you could try it out without drilling your cavitation plate.

Just got a 17' with a 120 Merc I/O I'm trying to get running. Its' cavitation plate is drilled for a hydrofoil but there's not one on it. I'm going to try it next year with and without a hydrofoil. Also plan to try some Smart Tabs on it, everybody who's tried them really seems to like them.

 

[tashasdaddy]

Re: Hydrofoil query again..............sorry.

good iboaters don't recommend foils, except to people they don't like. smart tabs.

 

[Silvertip]

Re: Hydrofoil query again..............sorry.

The amount of fuel you would save over the life of the boat would not likely pay for the hydrofoil. I've owned them twice and removed them twice. They can upset handling on a boat but that depends to a degree on the style of hull. Don't you think that the engine and outdrive manufacturers have tested these things and if there was an advantage the engine AV plate would be designed like a hydrofoil.

 

[dimock44]

Re: Hydrofoil query again..............sorry.

I have had them on 3 boats and took them off because of poor handling in turns. One of them was just plain scary. I have smart tabs in my 17 ft semi V and they work really well at not that much more cost. No way to tell about fuel savings but there must be some since it planes out at lower rpms.

 

[steelespike]

Re: Hydrofoil query again..............sorry.

While I have had good luck with foils on a 50hp. 15 ft Starcraft and a 18ft 120hp Cobia I now would only reccomend something like smart tabs.These are very effective ,helps plane easier,improves handling,stops no wake wandering.
I'm sure they would improve mileage at some points of the operation range.
The foil might improve mileage by lowering power required to get on plane
but I think it might hurt mileage both above and below planing speed.
Gallons per hour remains the same for a given hp. Smart tabs help get the best performance from that GPH rating.

 

[mfcoloradonf]

Re: Hydrofoil query again..............sorry.

Forget hydrofoils....Go with some smart tabs SX. You can get the here on iboats for about $120 bucks. Read my other post about them.

 

[QC]

Re: Hydrofoil query again..............sorry.

To be fair, although I have always hated them, some people like 45 Auto have reported decent results with Hydrofoils. With that said, very inconsistent, potentially dangerous, and those who have not tried some sort of trim tab system are simply missing out on a MAJOR improvement to all V-hulls. ALL.

Friends don't let friends use Hydrofoils . . .

 

[guy74]

Re: Hydrofoil query again..............sorry.

Don't you think that the engine and outdrive manufacturers have tested these things and if there was an advantage the engine AV plate would be designed like a hydrofoil.

I love that remark, but it begs the answer of if smart tabs are such an improvement wouldn't boat manufacturers all put the on from the factory? I like my Sea Sport foil, I wouldn't be without it on my setup. I would guess that any damage to the motor is from people useing it for a step, or backing it into something. In other words abuse not use. I would try trim tabs, but they are too high priced, and I'm not fond of drilling more holes into my transom. I have never experienced any downside to having the Sea Sport on my boat, but it is only a 50mph boat with a 100hp motor. You might get into other dynamics on a highspeed boat. Just my 2c. Everyone else voices their opinion on this, I might as well.

 

[a2theb]

Re: Hydrofoil query again..............sorry.

Well, I just got my first new to me boat and it came with one installed. I haven't gotten it into the water yet! Based on the general consensus, it looks like I'll be removing the hydrofoil this weekend.

 

[rndn]

Re: Hydrofoil query again..............sorry.

I had a 1989 Baja Force 216 with a 5.7 mercruiser alpha 1 and loved what my Sea Sport hydrofoil did for my boat. I used to have to ask people to get out of the back seats and stand towards the front in order to get the boat out of the water. If two people were sitting in the back seat the boat would not get out of the water. After the hydrofoil was installed the boat launched with three people in the back with no problems. It also did not affect my 64 mph (GPS top speed) at all. I'm sure it would have even been better with tabs, but this worked for me. I had the foil on for 10 years and never had a problem. The person who bought the boat from me 6 years ago was still using the foil last I knew.

 

[Maclin]

Re: Hydrofoil query again..............sorry.

They can affect the handling during turning in a negative and sometimes dramatic way on some boats. My brother's Sidewinder would scare the crap out of his kids in the back when it turned. I finally noticed the foil on his drive and said I thought it was lifting too much during the turns so we tried it without and the turning was better. It used to kind of fall into the turn, not much fun for the people in the back looking like they were about to land in a wall of water.

They lift from the middle of the boat and that is not a stable condition. Trim tabs on either side are much more stable and let the hull do it's thing.

 

[guy74]

Re: Hydrofoil query again..............sorry.

One thing I wonder about is the design of the foil itself. My Sea Sport foils are mostly behind the motor and don't stick out very far to the sides. It directs the thrust from the prop down, and realy helps launch the boat. It really helped tame the bowrise I had after adding a ski pylon to such a small boat. I have tried the boat with and without the foil on, during the same day, doing the same things. I like the way my boat handles with it on, so I guess thats why I like it.

 

[steelespike]

Re: Hydrofoil query again..............sorry.

Well, I just got my first new to me boat and it came with one installed. I haven't gotten it into the water yet! Based on the general consensus, it looks like I'll be removing the hydrofoil this weekend.

I wouldn't just remove the foil.See how it works.Properly installed it will help hole shot.And the boat will plane on less power.Keep the foil and if you want try it without.I'm sure it won't get up as easily.Plan on upgrading later with something like smart tabs.
Sometimes foils are put on to combat problems from a poor setup.

 

[QC]

Re: Hydrofoil query again..............sorry.

but it begs the answer of if smart tabs are such an improvement wouldn't boat manufacturers all put the on from the factory?

Well you answered this well in your next line . . . it is cost . . . With that said, almost anything decent, above 23 ft. or so, and helm adjustable tabs are standard

 

[a2theb]

Re: Hydrofoil query again..............sorry.

I wouldn't just remove the foil.See how it works.Properly installed it will help hole shot.And the boat will plane on less power.Keep the foil and if you want try it without.I'm sure it won't get up as easily.Plan on upgrading later with something like smart tabs.
Sometimes foils are put on to combat problems from a poor setup.

I guess is wouldn't hurt to give it a try. I am considering smart tabs though as I build up my boating experience.

 

[sickwilly]

Re: Hydrofoil query again..............sorry.

Your boat is perfect for a hydrofoil. I would recommend trying the SE sport 300.

As far as the rest of the opinions you just received, remember, opinions are like @##%$&^&, everyone has one, including me.

What a hydrofoil did for my boat is significantly decrease the amount of speed I need to plane. My boat turns wonderfully, and my last boat was a malibu skier, so I know what good turning is. My boat will hit 55 mpg, so I have no loss of top end.

Are smart tabs better. Likely this is the case, because so many people here love them.

Are hyrdrofoils worthless on a 19 foot boat -- no way!

Will it help with gas -- if you are worried about gas milage, you need to get into sailing


Other benefits to a hydrofoil that I like:
1- kids swimming behind the boat do not hit the prop (motor off of course), which gives the wife and kids added comfort.
2- they make you Kool!