Keel walking

[67hat34c]

There has been alot of talk about this problem in the past and some currently. Some have repowered older boats and at new higher speeds the problem is starting. I noticed that one member had new larger rudders made. I am wondering if larger rudders and enough toe in would cause enough torque to stop or minimize keel walking. also different rudder shapes such as flat on the inward side and slightly rounded on the outboard side, leading edge shape and trailing edge shape.

I bring up this because i remember back in the mid 80's i had a Ski Supreme, inboard ski boat which had a rudder and 3 fins. the boat had a problem of hunting left and right while in the slalom course. someone showed me how to load the rudder by slightly roughing up one of the trailing edges. this caused the boat to pull to one side if you let go of the wheel but it stopped the hunting which was far more anoying. I noticed on the new Ski Nautiques that there is and adjustible tab on the trailing edge of the rudder, suspect it is to comp for single engine torque.

Has anyone experimented with this or know anyone who has?

 

[TedZ]

Keel (chine)walking is a problem that can be dangerous. Toe-in is used when there is play in the rudders, steering etc. doubtful your problem.

You do not need horizontal forces (toe-in) but vertical ones. The typical fix is pads. God knows what size but i would bet that 2' by 2' out on the wet sides near the stern would stop it. Lot of experamentation needed. Not an easy proposition.

Ted

 

[Banshee36]

My rig keels walks like a champ, but it a 28kts, 25-26 its fine. If I wanted to run 28-33 all the time I would make the bottom of the keel into a sharp point. I would use coosa composites to makeit. I do not know if it would work, But I would rather do that than cut the keel down.
JW

 

[Wayne]

28 knots seems to be the magic number. My rig behaves the same. If I were going to test your theory I would begin by sharpening the keel forward and move aft only as far as necessary so as not to have a large impact on stern lift. I have been gunkholing in the Bahamas all year and love my keel.

 

[Genesis]

These hulls were just never designed to go that fast. If you're going to play with this PLEASE enlist someone who knows what they're doing. Its pretty easy to screw up the boat BIGTIME if this sort of correction is done wrong.

I agree that the keel is EXTREMELY valuable - I hit SOMETHING (never saw it) offshore a few years ago and all I got was a nice solid "THUMP!" It was deflected off and didn't get into the running gear.

I shut down, checked carefully inside for potential leaks (always first priority!), put on a mask and fins and went over the side to inspect for damage. A small spot about 3" long where the bottom paint was abraded on the keel was the extent of it - no gouges, nothing - just missing bottom paint.

Had the keel not been there I suspect what I would have had instead would have been "CRASH/SMUSH/GRIND/RIP/aw-@#$!@#!!"

 

[Maynard Rupp]

The keel is great. These boats track straight beautifully. It allows you to run aground without touching the props on the later boats with prop tunnels. If you need to get there that fast,hell, buy an airplane.

 

[Banshee36]

I agree with ya, I am not cutting off my keel, its there for a reason. I just thought that putting a point on the keel would lessen the keel walking, less surface area to ride on. As far as placement, on my 36 at 25-26 knots, the bow of the boat is out of the water to the front of the house, I would probably start the shaping there and go to the stern. But , its not happening any time soon, I'll just pull the throttles back. I think Tom slane has done some keel work, perhaps that is where I got the Idea.
I did see a tricked out 45 Hatteras last year that had the keel completely removed, it was on the hard at the Fishing Center.
JW

 

[67hat34c]

What if you make a fiberglass strip that is pointed then screw it to the keel and try it out. if it works then attach perminently.

 

[34Hatt]

My 34' is doing it around 25 kts but boat was empty It now is loaded filling fuel tomorrow and moving it out east about a 3 hr run will have better feel by then. Wondering if extra weight makes a difference and deeper water?? Only have run it in 8' or less and missing 95% of stuff on board 3 nights of hauling stuff to boat has taking care of that . And if not I also would never cut the keel most of the time 20-23 kts will be sweet big jump from 14 kts.

 

[34Hatt]

Ok ran it for a 3 hr run this weekend. All different conditions thru many different bays. I did one short blast to the pins right before my marina this was is deeper water 40' +, boat is better in deep water. Filling with fuel did not make a difference and boat has not really lost any speed with loading it and filling fuel it hit 26.5 kts against a 1.5 kt current wind at the side. Most of the run I ran 2250 550 of the pins and she handled great and was doing 22kts over the water.

 

[ELECTRA VI]

Sounds good Dan. Makes me wonder what ELECTRA VI would have done if I put in the 315s. Oh well, I am happy at 17-18 knots cruise. Better than the 13 I got with the 454s without cutting in the 4barrels.

 

[34Hatt]

Well Bob I would say that it would be the same or real close as mine cause the Cummins 330B is 315 hp the 330 is the Metric rating they always have to throw that curve ball in there .