Boat not level on plane -- please help :)

Hello everyone,
I have a 1991 Thundercraft boat, with a mercruiser alpha 1 outdrive. When we get on plane, the boat seems to learch side to side with out us doing anything. Its like the center of the boats gravity changes and it tilts sideways, which can be heart stopping when you are moving at high speeds. There is nothing wrong with our outdrive. And its not the wind, because it happens everytime we take it out.
any thoughts?
-Bill

Re: Boat not level on plane -- please help

Is this a glass boat or tin?
With Tin you can tune the hull, just in front of the transom, I was shocked how much 1/16th of an inch makes. Tools are a 2x 4 and a hammer/ and a level to check for true front to back/side to side.

With glass it could be a bunch of things, waterlogged below the floor, sloshing back n forth, or outdrive may be off kilter... good luck

Re: Boat not level on plane -- please help

Welcome to iboats

Almost sounds like chine walking read this http://www.bassboatcentral.com/new_page_2.htm

and this c&p

Handling Chine Walk

Chine walk is a back-and-forth wobbling effect of the hull created when hydrodynamic forces try to balance the boat up on the primary pad and the supporting lifting strakes on each side of the pad. Each time a propeller blade enters the water and another exits, they are constantly trying to throw the boat off the pad. Now, if the prop is getting too much bite, it creates chine walking. This is typically results from improper rigging - not setting the motor at the right height.

Chine walk can be dangerous and can cause a wreck if it gets out of control. Do not try to drive a boat through a chine walk. Some boat drivers think if they keep trimming and adding power, the boat will stabilize itself. This kind of thinking will get you in trouble. The only way to eliminate chine walking is to reduce power and solve the problem either by adjusting the engine height and/or learning the proper way to drive your performance hull.

Re: Boat not level on plane -- please help

its a fiberglass hull, and it does it and usually stays at a left or right angle, until somone in the boat moves to the opposite side, then it goes to the opposite side.

Re: Boat not level on plane -- please help

its a fiberglass hull, and it does it and usually stays at a left or right angle, until somone in the boat moves to the opposite side, then it goes to the opposite side. Its not a chine walk its not that aggressive. it just leans to one side until somone moves to the opposite side then leans to that side.

Re: Boat not level on plane -- please help

It also sounds like you may have the bow trimmed too far down, have you tried trimming the power trim out a bit?

Re: Boat not level on plane -- please help

No, will try next time we are out. What else could it be so i can try a bunch of things?
-Bill

Re: Boat not level on plane -- please help

Any fin(s) on the outdrive? What all is mounted on the transom? Got any pics of the stern from a low angle? Has the hull been not supported during storage/trailered maybe, and is misshapen?

Re: Boat not level on plane -- please help

The boat has always been stored and trailered correctly. as for the outdrive, it is just a normal alpha one, nothing on transome.

Re: Boat not level on plane -- please help

tibklers002 said:

No, will try next time we are out. What else could it be so i can try a bunch of things?
-Bill

Click to expand...

Since the boat falls off to either side I don't feel that there is an issue with the hull shape. If the boat is trimmed bow down too far the sharp forward sections of the boat will be immersed too deeply in the water. This causes pressure to build up on one side or the other and will cause the boat to want to veer off course to port or starboard. When a small amount of steering correction is applied the boat will lean to one side. This is known as "bow steering" and with boats that have mechanical steering you will feel the helm fighting you (not so much if you have hydraulic or power steering such as in an I/O).

One tip, try only one thing at a time the next time you run the boat so you know which change corrects the problem.