Page 1 of 1

Slow Speed Wandering

Posted: Tue Jan 19, 2016 12:49 pm
by X23
Operating some planning hull boats at low speed requires constant attention to the helm, as the vessel wants to turn one way or the other all the time. This is quite annoying in the many “no wake” zones.

Other similar boats hold a straight course when stable, without attention.

Has anyone else noticed this? I would also appreciate your thoughts on hull design for good behavior in all speed ranges. Or to put it another way, what features would contribute to the wandering (assuming all play is out of the steering system).

I'm trying to decide on which cruiser plan would best suit my needs.

Thanks,

Re: Slow Speed Wandering

Posted: Tue Jan 19, 2016 3:56 pm
by hoodman
I think the steering system has a lot to do with it. A no-feedback system will help to keep the torque of the prop from causing the steering to wander.

Re: Slow Speed Wandering

Posted: Tue Jan 19, 2016 4:20 pm
by kens
Double Eagle is a design that runs well at all speeds. A lot has to do whether it is a inboard or outboard motor, inboards do not have a 'hump' to get over to get up on plane. A semi displacement hull form runs well at the speed you mention

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 4:09 am
by Randeb74
Exactly! Glad to hear someone else address this very real concern. Have you found any answers to it or understanding of the phenomenon?

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 6:37 am
by Bill Edmundson
My Bartender wanders also. It does great with a little throttle. My BT has an outboard in an inboard well. I thought that it is because the engine is close to the forefoot. At low speed I have to watch for the first sign of turn at the bow and back off. I have hydraulic steering and it is tight. I just though of maybe a small skeg or fin aft of the engine might help. I know that is not an option for anybody else.

It's interesting to know that it's not a unique problem to the design.

Bill

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 6:57 am
by chugalug
I noticed that on Floridaboys tugboat video too.thought he was doing it on purpose.maybe not.hope I don't on chug

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 8:17 am
by Jimbob
I think the wandering is common at low speed. I had a wellcraft 20 runabout that wandered at wake zone speed. Rather than constantly adjust the steering, if I just left the steering in place the boat would "weave" to the right and then back to the left, continuing on a straight course. When I went on the demo ride before I ordered my boat, the demo boat weaved right and left at low speed. The salesperson said the weaving was common and don't fight the controls.
Jim

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 8:36 am
by BillW
Deep-V hulls are usually hard to steer straight at displacement speed. It is so common, that it is known
as "Deep-V Wander"

Here is what is happening: The deep deadrise hull is acting somewhat like a flag waving in the wind. Pressure is slightly increasing
on one side of the bottom, while slightly decreasing on the other. This pulls the boat to one side, until the situation reverses.
Sort of like a flag.

Usually, the driver makes it worse, attempting to steer straight.

Bill

This may post twice; it didn't post the first try.

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 9:21 am
by Bill Edmundson
Bill

Thanks. I'll give that a try, But, outside of the marina first!

Bill

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 9:47 am
by neel thompson
Here is a link to a short discussion about slow speed wandering... http://www.boatingmag.com/how-to/contro ... eed-wander

Re: Slow Speed Wandering

Posted: Wed Sep 20, 2017 12:57 pm
by neel thompson
Here is another link to You Tube that shows outboard motor dual fin......https://www.youtube.com/watch?v=k-8La_bT3D0