Ring Powerboat stability problems please any help appreciated

[adrian_uk17]

Well i have just bought a 16ft Ring powerboat, went out with the owner the first time, and she ran really well and the engine was sound.

Took her out another time with a friend and she was also fine.

Took her out the water after this, drained a little bit of water from the bilge about 5 litres, she had been sat in the water for 3 days and probably took on some water by plughing through a couple of waves?

Anyway when we got her out the water we notices a couple of nasty chips in the gelcoat, so i patched these up.

Next time we took her out at a reasonably high speen the boat begins to really lean to one side, to the point that you have to back of or risk flipping her over. And she has done is on both side, not just one side?

I have checked everything, and i have tried all different trims and she still does it, and i have no idea now as to what is causing it.

Any help will be greatly appreciated?

[gonzo]

There is a good article about heeling at planing speeds in the last issue of "Professional Boatbuilder". It seems like a typical design problem. What you encounter is a dynamic lift , or lack of, problem.

[adrian_uk17]

Thank you very much Gonzo, the only problem is that i am on the other side of the atlantic, UK. And i cannot get a copy of this article.

I would find it very strange that the boat would do this, as it is a production design boat, and the fact that it suddenly started doing this out of the blue is a mistery?

What i am inclined to the cause is the engine having its outboard skep below the prop is slightly mis alligned?

Could this be the cause?

[adrian_uk17]

Anyone else got any ideas, i am really baffled now as to what could be causing this boat to heel heavily to either side under certain speed conditions?

Anyone clever person out there that can help?

[Paul B]

Is there any possibility that your small cracks have allowed significant water in that has become trapped in a compartment (maybe under a floor or tanks)?

If so, the water would flow to one side or the other in a turn. This would cause a good bit of instability.

Fuel and water tanks have baffles in them to stop the surges of this "free surface".

[Alan Power]

Adrian, have you changed the prop or damaged the skeg or bottom in any way. What speeds are you running, do you have trim tabs. How many times has this happened, is it possible to drive the boat out of the heel.

I ALSO HAD A RING 16 AND MY BOAT DID EXACTLY THE SAME AS YOURS.I SPOKE TO MIKE RING THE DESIGNER AND HE TOLD ME THAT THIS WOULD HAPPEN MORE ON A LAKE WHICH IS MORE OR LESS FLAT.BECAUSE THE BOAT HAS A DEEP VEE HULL WHICH IS DESIGNED FOR THE ROUGH WATER OF THE SEA.IT WOULD NOT HAPPEN AS MUCH ON THE SEA.THE REMEDY IS WHEN THE BOAT LEANS TO THE LEFT JUST AS IT STARTS TO HAPPEN STEER SLIGHTLY TO THE RIGHT AND VICE VERSA TO COUNTER ACT THE PENDALUM AFFECT.RING POWERBOATS ARE GREAT BOATS AND HAVE GREAT HANDLING.I HAVE NOW PURCHASED ANOTHER RING -A RING 21 WITH A HYPERFORMANCE OFFSHORE RACING ENGINE AND THE BOATS REACHES SPEEDS IN EXCESS OF 80MPH AND THE HANDLING IS 100%

HOPE THIS HELPS.