Cruising Spinnaker (Asymmetric Downwind Sail)
by Capt Al Watson, Kindred Spirit #55
Setting a Cruising Spinnaker using Parrel Beads, rolling over the furled genoa
A Cruising Spinnaker with a dousing sock can be a useful sail when downwind sailing with much less effort than using a spinnaker with pole. I stress the word CRUISING, as this is my type of sailing. For racing with an asymmetrical, see Ron and Mike's comments attached at the end of the article.
The tack of the sail may be connected to the bow in different configurations. To set a Cruising Spinnaker (Asymmetric downwind sail), first attach the halyard to the head ring on the sail. If your boat has a roller furling genoa, it is recommended that you use a set of PARREL BEADS that are wrapped around the furled genoa and then snap-shackled to the tack of the sail. Parallel beads are solid nylon balls with holes drilled through them, through which a wire cable passes. The cable has stainless-steel thimbles at either end that are then shackled to the tack, making a closed loop of beads around the genoa. The parrel beads roll over the furled genoa, allowing the tack of the cruising spinnaker to be raised and lowered with ease.
Next tie the tack downhaul line to the tack ring, leading it through a turning block on the deck near the bow, and run it aft to the cockpit. Set up the tack downhaul so the tack of the sail is about five feet above the deck when the sail is hoisted. Attach the spinnaker sheet to the clew ring of the spinnaker and make sure the line is led aft outside the lifelines to a turning block on the toe rail located just forward of the stern pulpit. Then run it forward to a winch. The sheet that is not being used, lazy sheet, should also be attached to the clew of the spinnaker, led forward in front of the head stay, and then back on the other side of the boat outside the shrouds and lifelines to another turning block positioned just forward of the stern pulpit. Then take that sheet and lead it to a winch. Once the sail is fully hoisted, and you head to your desired course you have two basic adjustments; the first deals with the height of the tack above the deck, and the second is the amount of sheet you should pull in for any given point of sail. A cruising spinnaker should be trimmed just enough to stop the luff from curling. Adjust the tack height so the middle of the luff curls first when you head the boat up into the wind. If the upper part of the luff curls first, the tack is too high and must be lowered. Conversely, if the lower part of the luff starts to curl first, the tack is too low. Which brings us back to where we started, adjusting the tack from the cockpit not having to run forward.
If this all makes me sound smart, thank you but I must give credit to Neil Pryde Yachtsail Newsletter. It is very informative.
The above will work fine, but I've refined a few aspects of this configuration. I attach a snatch block to the bow roller. I run a tack line through this block along the deck through 2 small snatch blocks to the secondary winch for tack height adjustment. The tack line has a carbinner at the tack end for quick disconect. The harness described that is placed around the furled headsail limits your downwind performance. With the tack moved forward and allowed to free fly you can project more sail area at higher apparent wind angles giving you more horsepower. It also allows you to drive deeper (higher apparent wind angles) than when the tack is attached to the furled headsail. Another step to improve downwind performance (higher AW angles would be a reaching strut utilized as a bowsprit pole). If you plan to race with an asymmetrical chute it is advisable to place moveable ballast (crew) on the leeward rail to project more sail allowing you to drive deeper on the downwind legs. You may also want to let the head of the chute out (ease the halyard) and this also allows more sail to be projected. The author of the above is right on with regard to trimming.
Keep in mind an asymmetrical when it collapses is handled the opposite of a symmetrical. With the asymmetrical you come up on the helm and trim the sheet to fill versus pushing the vessel down with a symmetrical. I've heard some figures reference the usable angles and testing shows that an asymmetrical is more efficient than a symmetrical 60-120 degrees AW.
It is sometimes possible to extend this to 135 if you can get the tack forward of the bow.
Over the 120 to 135 it is best to use a pole and a symmetrical kite as your VMG will suffer at high AW angles.
Ron Euler, GONE WITH THE WIND, Naples, FL
We use an asymmetrical on "Pisces" for racing. Our tack line is lead to a block attached to a pin on our anchor bow roller and then back thru a stopper to the port cabin top winch. The block is located inside the pulpit and in front of the head stay. At this time phrf limits the height that you can adjust the tack above the deck and no pole can be used with it with out extra penlty. Ron is right on with his comments. I want to add that the parrel beads would be good for the tighter wind angles (60-110) and cruising type asymetricals. Some Racing Asymetricals are cut fuller and designed to roll around the front of the head stay for running (deeper wind angles 135-?) but the trade off is they require more attention to trim. Again I think wind strength can determine how low you can sail with it. We have sailed with the aw @ 160-? In the higher wind velocities with good vmg. What I like is that when the wind gets too strong for the sail we start rounding up or colasping it too much and know it's time to take it down.
Any way to make it work the tack must be able to be adjusted up or down and in front of the head stay.
Mike Roll, C30 Pisces