Saturday, March 9, 2019

Riding Sails

Some boats hunt all over the place in a breeze. Yawing through 90 degrees can double the force on the anchor and quadruple the forces working to twist it out. First, there are solutions related to the anchor and rode:
  • All chain. Helps right up until the chain lifts off the bottom.
  • Hammer lock mooring. A second anchor, just touching the bottom. Very effective in moderate wind, but can fail if strong enough.
  • Two anchors. A whole nuther' topic, but can work very well. Also complicated, particularly if there are other boats anchored nearby (you will swing differently).
  • Drogue on the chain. Didn't do much for me. You've got to be yawing fast for it to matter.
You can change your windage. After all, that is the source of the problem. Anything forward is like a riding sail at the wrong end.
  • Take the dinghy off the bow. Big difference.
  • Lower you reacher. Big difference.
  • Add a  riding sail aft. We'll come back to this.
And you can change your under water profile.
  • Lift the rudder. A HUGE help. But most people can't do this.
 I've been playing with riding sails. Single luff sails function by pushing the stern to one side, which creates a crude V. The problem is, it is very sensitive to how the boats windage changes with aspect change. Some it works, most not so much:
  • Push the boom to one side. Didn't do much for me. Yawed through the same angle, just to one side.
  • Riding sail. Same problem, plus it flaps when it reaches the extreme travel. Annoying.
I've also tried V-riding sails, with two luffs:

  • This is a Fin-Delta, from Banner Bay Marine. I've heard goo things and need to get my hands on one.

  • A less conventional approach is the V-Delta, conceived by Paratech but not marketed. Even this crude tarp was stable up to 25 knots. The grommets were set in a corner reinforced with only duct tape, and yet they didn't pull. The force is just not that great. It also reduce the yawing more than half, and the higher you set it, the better it works.

If  I didn't have  bridle, I'd be sewing one of these right now. So simple. Yes, it does increase the rode tension a few percent, but this is FAR less than the wind hitting the boat from the side and swinging it about.

Please share your riding sail experiences. I need to figure out what to test!


2 comments:

  1. Hi Drew glad to read this blog. Riding sails are the reason for visiting your site. Referred to you by Dave Lochner, a fellow Sabre owner. We sail a Sabre 425 from Rhode River near Galesville. Currently on our initial retirement cruise. Have ridden out several 20+ blows and unhappy with 'swing'. Tried a flat triangular style attached to topping lift. Backstay unavailable, cluttered with Bimini and radar mount. Very interested in the over the boom style. Unsuitable for us because of lazy jack lines but wonder about rigging side panels to Bimini.
    Welcome your thoughts.
    Rick and Judy
    Innisfree

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  2. The mast is well forward on the that boat and some have cutter rigs, both or which place a lot of windage forward. If you have a Bimini, you already have a lot of windage aft too, but I think I would try a Fin Delta. Since the blog entry I got one for testing and it was the most effective design. The are a little pricey, but they are highly effective and can be rigged high, clear of everything but lazy jacks. Lazy jacks can and should be made so that they can be pulled forward, into the space behind the mast, while sailing and for hoisting in windy weather. It does take a few minutes of fooling to get the line lengths right (as far back and as wide as possible), but the it's fast.

    I wouldn't be surprised if you could return the Fin Delta if it does not work; a single trial or two won't put any wear on it.

    The other thing to try is a hammerlock mooring. Lower a second anchor until it just drags a little on the bottom. Not set, and not enough to tangle. For example, less than 20 feet in 10 feet of water. That can really help.

    I have articles on yawing and riding sails coming out in Practical Sailor magazine, but I don't know when.

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