Demystifying Cruising Spinnakers
Below Top: Spinnaker sock makes hoisting and dousing very easy. Bottom: Spinnaker rigged with sock raised out of the bag.
If you’ve been enjoying the Northwest waters by sailing downwind wing and wing, it may be time to enhance your off-wind performance. Adding an easily handled cruising spinnaker (also known as gennakers, asymmetrical, etc) can quickly increase your speed off the wind in the usual light to moderate winds we see during the summer and fall seasons.
By Jack Christiansen Over the last 20 years the
asymmetrical sail shapes have evolved and have been continually refined. Cruising spinnakers are specifically designed with a “wide groove” to ensure the sail will fly over a broad range of wind angles. This is particularly important when sailing with autopilot steering. Cruising spinnakers are usually offered in distinct models, one of which will be a perfect fit for your boat and sailing style. Boats are fastest with the apparent
wind at the beam. A cruising spinnaker is more efficient at this angle than a genoa due to the larger area and fuller, deeper shape. In this case a cruising spinnaker will be more efficient than a symmetrical spinnaker because it has a longer luff length that is going to pressurize easier. More importantly, a cruising spinnaker does not have the 48° NORTH, JULY 2011 PAGE 40
symmetrical spinnaker leech return. This return enables the spinnaker to be more effective “downwind,” but causes more stalling of the wind at tighter angles and in lighter air, which leads to collapsing spinnakers.
“What model is for me?” When someone talks about going
faster off the wind, I repeatedly hear, “I want the biggest and deepest running chute I can get.” It is unbelievable to many (but true), that a boat flying a symmetric spinnaker on a spinnaker pole can’t go efficiently dead downwind if it is blowing under 12 knots of wind. In the 8 knots of wind typical in the Northwest, you will be sailing angles that put your masthead fly from 85°–100° AWA (apparent wind angle). These are prime angles for a medium sized reaching asymmetric.
As it gets windier you will be able to sail deeper as more wind gets around the mainsail. You can also ease your tack line up, artificially lengthening the luff to give the sail more of a running shape, which allows the luff to rotate out to windward. In lighter air and tighter angles, tighten the tack line to bring the tack down to the top of the bow pulpit, or just below, for a more efficient shape. Other models to consider would
be a G-0 or Code 0 and G-2. The G-0 is for tighter angles such as 55 AWA in 3 knots of wind to 90 AWA in 18 knots of wind. It might be built out of a light laminate material or heavy nylon or polyester spinnaker cloth. This design has a straight luff that has a spectra luff line in it that is tensioned tightly, and
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