Steering under power

[biker]

I have a MacGregor 26D and have decided to do some Mississippi River cruising. The problem is when I'm under power (Merc 9.9) the boat wonders all over the place. If I don't pay very close attention the boat will do a hard left and more often right, which could be very dangerous. It seem to be better when the keel is up but the cruisers just throw me all over the place, to avoid this I have to travel with the keel down. Any help would be a big help. Thanks from tired arm.

[a64pilot]

This is a water ballasted boat? If so is it different with ballast?
Sorry never been on one myself, just a guess.

I think you mean it’s better with the keel down? Makes sense as a keel ought to give more directional stability

[Lepke]

When I was young I had a boat like yours, stern mounted outboard, and similar problem. Part of the problem is the engine is offset and the rudder isn't in the prop stream. I left the keel down because it helped keep the boat straight. I mage a jig that turned the outboard with the rudder and it made steering much better and allowed sharper turns. There's probably a commercial product.

[Cpt Pat]

Originally Posted by Lepke

When I was young I had a boat like yours, stern mounted outboard, and similar problem. Part of the problem is the engine is offset and the rudder isn't in the prop stream. I left the keel down because it helped keep the boat straight. I mage a jig that turned the outboard with the rudder and it made steering much better and allowed sharper turns. There's probably a commercial product.

I have the same problem: in my case the prop is aft of the rudder, which makes the yawing forces divergent. It wants to go in every direction but straight. In close quarters, I steer with the engine, and set the rudder amidships. Otherwise, I hope the CG doesn't think I've been drinking.

[biker]

Cpt Pat, Thanks for the help, its nice to talk to someone that understand my problem. The last thing that I tried was to remove the rudder completely and steer with the motor. It seems to actually steer almost normal until I put the keel down and then the old problem comes back. The steering wheel people said that the problem was motor torque and to a point they were right. Not that I would do it but one solution might be to add a center keel the length of a boat.

a64pilot, I think if I ever ran with no water in the ballasted I would roll the boat very quickly. Also no it does steer much harder with the keel down.

Guys thanks for the help.

[Cheechako]

"Tiller auto pilot."

[sveinung]

Maybe adjust the trim tab on your outboard's cavitation plate?

[StuM]

Originally Posted by biker

a64pilot, I think if I ever ran with no water in the ballasted I would roll the boat very quickly. Also no it does steer much harder with the keel down.

I believe that the standard practice when motoring above 5-6 knots, is to have both the keel and the rudder raised. Also ensure that the ballast tank is full (or empty in very calm conditions if you want the extra speed), never partially full.