Stingray Hydrofoil for porpoising...

[Duff]

I'm looking for a way to fix the porpoising and swaying on my boat. I have trim tabs and I know how to use them but it isn't enough to fix the problem. Is this a waste of money?

http://www.whitworths.com.au/products/36543_lg.jpg

[Mont]

Duff, I had those on my Wellcraft. If you want the bow to ride a little lower, they will do the trick. The other thing you can do is figure a way to get some more weight in the front. The only thing I didn't care for about them was it was hard to get the bow high enough when the weather got rough out there. It wasn't a real problem, because I was always pretty careful about the weather but we all know how fast those summer time storms can brew up out there.

[Howard/Jax]

The hydrofoils are OK in calm water. However, they do put a considerable strain on the Cavitation plate. Remember that you do have to drill holes in cast aluminum. I think that Monty's idea of a bit of addition weight in the bow, is a good one. This is on the advice of my service manager, with well over 50 years working on OBs and IOs. Just another bit of info. Always have your trim tabs in the bow up position when not needing to trim the boat. Some folks think that if they put the trim tabs in the bow down position when taking off, it will aide the time in getting on plane. All it does at that time is lift the stern and most likely will cause the lower unit to cavitate. You want the prop pushing you forward, not up at the stern.

[DanS/FL]

Give us a little more info. I never cared for the fins you show. In my opion all they were any good for was to give a little more hole shot.
Boat
Length, width, weight.

Motor,
HP, weight, brand name

A picture, if you have it, of the boat setting in the water. If not ,on the trailer So we can see the stern and side.
That should give us a start,, ~~~ Dan

[~~Snakeman~~]

If you do decide to buy anything, Boater's World is going out of business. There are two locations in Palm Beach County. Their close-out sale may save you something.

~~Greg~~

[Duff]

It's a 22 Sea Fox center console Dan. I'd say the beam is about 8' and I'm not sure about the weight. Even with 113 gallons of fuel it seems like it isn't heavy enough. It tends to bounce around more than it should unless I have 8 people in the boat. Maybe it is the all composite materials and foam flotation... Maybe I am just used to that old heavy anacapri I had.

The Sea Fox is rated for 150HP max and I have a Johnzuki 140 on it. I've had 500 pounds of grown adults riding the bow of the boat and that helps, but I don't always have a couple fat friends readily available for weight balancing (any volunteers??) and there isn't much storage room to move anything to the front of the boat. The fishbox is in the front and when I can buy ice by the bushels that helps some. But also I'd like to get the chinewalking under control... I don't always go out when it is flat calm and the boat needs more stability in my opinion...

http://www.greengrouper.com/duff/boat5.jpg

[Zane]

Bat Breath and I volunteer, that covers the bow 500#

[Howard/Jax]

Are you telling us that Batbreath is now close to 300lbs?

[Zane]

LOL right weight, probably wrong guy :mad: :mad:

[Jack Hexter]

I can't see the engine mounting in the pix, but is there any way to drop it one hole? Or is there a pin holding the engine out away from the transom that could be removed to tuck it in more. Generally, tucking the engine all the way down and/or lowering it will stop porpoising.

[Jack Hexter]

If you do decide to buy anything, Boater's World is going out of business. There are two locations in Palm Beach County. Their close-out sale may save you something.

~~Greg~~

Greg

BW going out of business sales may not be all that great. Check out the thred on the Pensacola Fishing Forum

http://pensacolafishingforum.com/fishingforum/Topic304716-2-1.aspx

[DanS/FL]

Jack made a good call. That was my first suggestion. There has to be a way to tuck that engin under more. When you get up on a plane where do you keep your tilt. Down, up, inbetween. You do have a power tilt don't you?
Dan

[Howard/Jax]

I have not seen one in awhile, but there use to be a wedge that would go between the transom and the engine that would be wider at the top and give you more tuck. Jack is also correct. Check your engine position. The cavitation plate should be flush with the bottom of the hull at the transom. Having it too high will cause both the Porpoising and cause cavitation.

[Duff]

Not sure if you can see the motor positioning from this picture or not...

http://www.greengrouper.com/duff/boat/P660_FL%209076%20%231.JPG

[Jack Hexter]

From what I can see, it appears the engine is as low as it can go onthe mounting bracket but there may be one lower position. Photo gets too grainiy when I enlarge it to see clearly. There does not seem to be any restriction bar crossing the mounting bracket to keep it from tucking in. You may have to look for the wedge that Howard wrote about. I'd try that before the HydroFoil. Like Dan said, the only thing I've seen them good for was a hole shot, getting up on plane fast.

[Howard/Jax]

There are several makers of the wedges. Just google transom wedges. They generally will give you 5º more tuck. Just remember THICK side up. Did you trim the engine down all the way to see where the cavitation plate sits with the lowest part of the hull?

[Joe/GA]

Hey Duff. I had a porpoising on my Scout. I had a heavy 4 stroke motor on the back. I also got a lot of torque list. After I put on a set of Bennett trim tabs, I had no more troubles. MOst of the time, I only needed them level. The port tab had to be down just a bit more to counter act the torque issue. I't hard to tell in the picture, but perhaps your tabs are too small for your boat. If they are Bennetts and they are not doing the trick, Bennett will work with you to make it right. Do a search on the Florida sportsman magazine forum and you will find countless cases where they helped people with trim tab issues. Usually, it is free of charge. They have the best customer service that I have ever seen anywhere! Did you buy your boat from a dealer set up that way? Maybe they will make it right? Good luck!