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Old 11-06-2021, 12:36   #31
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Join Date: Feb 2011
Location: Washington, san juan islands
Boat: true north cutter 34
Posts: 88
Re: Boat pulls to starboard

Likely just strong prop wash, nothing too alarming. But there are factors that can make that prop wash worse
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Old 11-06-2021, 16:44   #32
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Location: Sodus Bay, US (south) side of Lake Ontario
Boat: Pacific Seacraft Crealock 34
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Re: Boat pulls to starboard

I’ve had this problem with two boats. On the first the problem was a subtle warp in the rudder, the worse spot was in line with the prop wash. The warp caused an “airplane wing” lift effect pulling the rudder to starboard which turned the boat to starboard. It was more easily detected by holding a straightedge against the rudder. The warp did not affect performance under sail because without prop wash there wasn’t enough “lift” to displace the rudder. It was a brand new boat and the manufacturer replaced the rudder - problem solved.

The second boat the turning problem was more subtle, but still annoying. No obvious cause ever detected. Again under power only. The solution? - a small bronze trim tab about 6-8” high by 3” chord (fore to aft), about 1/16” thick, bolted to the trailing edge of the rudder in line with the prop wash. You bend the tab in the direction that the rudder wants to turn. It takes a bit of experimentation to get the right amount of bend, but on my boat about 5 degrees was plenty. No effect under sail, just power. I got the sheet bronze on eBay from sites for jewelry makers. If I recall correctly it came as a 8”x8” piece.

Good luck. Hope this helps.
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Old 11-06-2021, 17:22   #33
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Re: Boat pulls to starboard

I found can old photo of the bronze trim tab. There’s some distortion from photographing through water but it should give you the idea.
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Old 12-06-2021, 11:38   #34
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Location: Port Charlotte, FL
Boat: Freedom 38
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Re: Boat pulls to starboard

So many possibilities. With a righthand rotating prop, prop walk going forward should pull the stern to starboard - turning the he bow to port. On our Freedom 38 the prop walk is so gentle it is barely perceptible. Same for our previous boat - a Freedom 30. If engine/shaft were sufficiently misaligned to create a steering problem, you would likely feel vibration under power… unless the engine & shaft are aligned with each other but he entire engine is off to one side. You can inspect for this next time the boat is out of the water. The shaft should be pretty much centered in the shaft log where it exits the hull. A diver could make this inspection if your water is relatively clear. Another possibility is misalignment between rudder & keel. Sometimes this is caused by worn rudder bearings permitting excessive lateral play or improper alignment of the rudder if/when rudder bearings were replaced. A diver can check for loose/worn rudder bearings. Another cause of keel & rudder misalignment would be grounding impact to the keel. This would need to be inspected with the boat out of the water. You need to stand about 30 feet back from the bow and sight toward the stern along each side of the keel & rudder. The prow, keel and rudder should be in alignment. While Freedoms are known for having very strong keel structure & keel to sump joints, the keel is lead & can be deflected to one side or the other in a hard grounding.
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Old 12-06-2021, 11:48   #35
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Re: Boat pulls to starboard

Quote:
Originally Posted by Sailmon View Post
So many possibilities. With a righthand rotating prop, prop walk going forward should pull the stern to starboard -.
My dad, a boatbuilder, shipwright, Naval Architect, Marine Surveyor, FRINA, said that it was difficult to tell before the boat actually went in the water, which way it would propwalk. He worked in several shipyards, as well as designing many small boats (sailing and motor), from 20ft to 80ft.
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Old 13-06-2021, 12:46   #36
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Re: Boat pulls to starboard

FYI, as suggested, the issue goes away when not powered by engine. Thanks
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Old 13-06-2021, 12:47   #37
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Re: Boat pulls to starboard

You were all correct, no issue with no engine
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Old 13-06-2021, 13:06   #38
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Re: Boat pulls to starboard

Maybe you should check your wheel alignment
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Old 13-06-2021, 13:41   #39
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Re: Boat pulls to starboard

I would expect difference between sailing & motoring. In sailing the rudder is gliding through the water & the sails are applying force to the mast - which is well forward of amidships (cat sloop rig)… essentially pulling the boat along. The propulsive (is there such a word?) force from the propeller is directly in front of the rudder forcing water over it. You said something interesting in your original post. You mentioned that the wheel actually pulls - rather than saying the boat drifts to starboard. Also that the faster you go, the more it pulls. Because it doesn’t happen when sailing it suggests it is the wash from the propeller putting pressure on the rudder/steering system. I’d still be inclined to check the rudder for loose bearings & for centered alignment port to starboard.
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