Stabilizers

[TonyS]

I have a 16.5 foot bowrider with 3.0L OMC. I was just looking for better/faster planning. I have seen several boats with these stabilizers on the outdrives. They advertise that you plane in half the time. Asked at a few marinas, some said it will help a boat my size, but after 18 or 19", not much good. Most say that it helpd outboards more. Just wondering if anyone has experiences or comments. They go for between 80 & 100 cdn$. Boat is 1990, so not interested in several hundred dollars for trim tabs, another suggestion by a mechenic.<br /><br />Thanks,

 

[SS182]

Re: Stabilizers

Much talk about hydrofoils on this site and others. Use the search function to read other peoples experinces. I have an 18' bowrider and it did a lot of good as far as planning and stability for us. It did cut about 5mph off of our WOT speed, but 55mph is still fast enough!<br /><br />SS182

 

[TonyS]

Re: Stabilizers

New to boating, did not realize about the amount of posting on the topic. So, I appreciate your response, the search gave me alot of info. thanks.

 

[SS182]

Re: Stabilizers

No problem, there is a lot of very intelligent poeple on this board... and I have learned a lot.. welcome

 

[cobra 3.0]

Re: Stabilizers

I have a Stingray hydrofoil on my 16'boat with an OMC 3.0 Cobra and 17" pitch prop. It shoots to plane with it! Well worthwhile for skiing, boarding, and tubing. <br /><br />To read on the product:<br /><br /> http://www.marine-dynamics.com/

 

[TonyS]

Re: Stabilizers

I finally installed the Stingray Hydrofoil, and it worked great. The boat came out of the water alot faster, really amazing the difference. There is one funny change. The boat seems to list to one side or another with even minor weight diffences, i.e. due to different people's weight. We tried moving people arounf, hard to get it completely level. You really notice the change if you move a person from one side of the boat, also more noticable at higher speeds. Anyone notice these kind of reaction after installing one of these hydrofoils?

 

[Jdeagro]

Re: Stabilizers

Your side to side pitch is common on many V bottom boats when the focal point of the lift is in the center. The increased size of the cavitation plate (the hydrofoil increases the surface area of the A/C plate) lifts the boat from the center creating a teeter totter effect, and the faster the boat goes the more lift. The problem is a bow down effect when running at cruising speeds which allows the BOW to steer the boat. In short you have too much stern lift after you are on plane. Trimming the motor out will help some. When you are running at higher speeds the front of the boat should be up and out of the water. The splash on the sides should be toward the last 1/3 of the boat. If it is forward of that, then the bow is being forced down. You would also notice a reduction in top speed. Look at Trim Tabs or Smart Tabs in a search on this forum.

 

[Ralph 123]

Re: Stabilizers

I have twins and need and use both tabs and hydrofoils. The combo gets me on plane a lot fater than either one alone.<br /><br />Also, checkout these - they are like tabs (not foils) that fit right on your i/o<br /><br /> http://www.permatrimmarine.com/ <br /><br />The permatrim works differently to the Stingray , doelfin and SE 300 hydrofoils, by using the water that comes of the top of the propeller (the<br />hump you get out the back of the motor) and holding that down so you get more lift and thrust from the same amount of power.The other brands work like a aircraft wing, where the water rushing over them gives you lift

 

[Floyd]

Re: Stabilizers

I don't think that any of the hydrofoils work like an airplane wing, even if they are shaped like one. An aircraft wing creates lift by having the top surface more curved than the bottom surface. The common explanation is that the air flowing over the top of the wing takes a longer path than the air on the bottom, and is therefore "stretched out" a bit, causing a partial vacuum, which results in a type of suction on the top of the wing, and draws the plane up. if you watch a small plane, you might see that it's going up, even though it might be pointing straight ahead.<br />Since water is not compressible, the shape of a hydrofoil isn't as inportant, since it mainly acts as a steering vane or lifting surface. In fact, the ones that are thick like a wing might actually cause more drag than a thin metal one.

 

[walleyehed]

Re: Stabilizers

I tried to stay out, but I can't so here goes......The reason the wing "Flies" is the curvature of the top surface causes the air to speed up which creates a low pressure area above, and the area below stays basically the same, so high pressure overcomes the low pressure area and Wa-laaaaaa!!!!! LIFT!!!<br /> AS far as a "FOIL" shape to the fins, the idea is to separate the water at the leading edge with a sharp surface and come back together smoothly off the trailing edge. A flat piece of aluminum does not have the "sharp" leading edge, and the water completely separates from it for about 1/2 of the fin, which means higher drag, and only half of the fin works at top speed.<br /> A hydrofoil on the other hand has the complete bottom surface contacting water and the top fwd half as well. The "HYDROFOIL" will give better performance overall, just because of the streamlined design. It's much more stable at top-speed too!!!

 

[Ralph 123]

Re: Stabilizers

This text about how each works comes from the maker of the permatrim in an answer to a question about the difference.<br /><br />This is from the maker of the Stingray hydro-foil:<br /><br />The Sting Ray Hydrofoil Stabilizer applies the laws of physics to provide the extra performance every boat needs. It's aerodynamic design creates a higher water pressure on the underside of the hydrofoil surface, which creates lift to bring the stern up and force the bow down...<br /><br />It's patented, high-tech shape causes water to flow over its surface, hydrodynamically creating upward thrust pressure on the underside surface. Scientific principles go to work the moment the propeller start turning. Up-ward pressure lifts the hull, resulting in less drag since less of the boat is in the water. Sting Ray's wings then stabilize the water pressure, keeping the boat stable and safe. By staying in the water, the Sting Ray keeps on working.

 

[TonyS]

Re: Stabilizers

Hi Nautijohn, thanks for the info, I will play with the outdrive as you mentioned to see affect. Appreciate the time in responding.

 

[Jdeagro]

Re: Stabilizers

TS;<br /><br />Your welcome! I do not belong to the Hydrofoil fan club as you will notice, and I do have a vested interest in other devices. However, you may be able to cure some of the issues, and you have not spent much money. If the problems persist or you think you can do better use this forum to get more info. Good Luck and Have fun!

 

[Jdeagro]

Re: Stabilizers

 

[TonyS]

Re: Stabilizers

Tried what nautijohn recommended, just raised outdrive a bit, and the side to side pitch was all but eliminated. Still comes out of the water very fast, and we maybe lost a 1 or 2 mph of top speed. So for the cost, pretty good results.

 

[Jdeagro]

Re: Stabilizers

The loss of top speed indicates that you are still running bow down, just not as much. Turns at high speed may get testy. Be carefull!