Nimble Rudder

Posted By: Mark N, Nimble Arctic, Jax FL
Date: 6/11/07 5:36a.m.

Report: outside forum guidelines

In Response To: Weather helm (Michael)

Michael, Hope that you are enjoying your Nimble. I read your first post above with some interest. As you can see below, my rudderboard can fully deploy and does not have any metal plates for support along the sides. Since the rudders on the handful of other rudderboard Nimbles that I have seen are very similar to mine, I suspect that somebody did some re-engineering on your boat in the past, and it sounds like it is not for the better. A partially lowered rudderboard moves rudder's center of effort farther aft from the pivot point. This gives the rudder a longer lever arm which means that any rudder forces (lee or weather helm) will be magnified. This requires you to put more force tiller to counteract the rudder forces. This is why you noticed more weather helm when you lowered the board. This also increases the loading on the rudder mounts which is never good. If you have sufficient rudder authority with the board up, I would refrain from lowereing it when sailing. If you do not have enough rudder authority when sailing and feel that you need the board, I would make whatever modifications are required so that the board will fully deploy. In either case, you can use the board when docking to give you better steering at slow slow speeds. The thing that is most striking about your post is that your boat "continues to pull very hard" in only 10 kts wind. This suggests to me that your rudder is not the primary problem and I am at a loss to tell you what is. With all sails up and well trimmed, I don't develop weather helm until the wind gets up to ~18 kts. In 10 kts of wind, my helm forces are minimal regardless of sail trim. I am sure that taking down the mizzen will decrease your weather helm, but that should not be needed. Is your forestay adjustable? If so, maybe you stick is tilted too far aft.