Orion sailing under asymmetric spinnaker

[Jim Walsh]

This photo was taken on October 3 this year. The wind was between 4 and 9 knots, I’m broad reaching from Bartlett Reef toward Fishers Island. I sailed between North Dumpling and South Dumpling Islands. This asymmetrical allows me to sail on a beam reach, which was handy because the wind direction changed while it was funneled through the islands, but I had to pay close attention at the wheel. I finally doused the sail when the wind dropped to 2.8 knots when I was adjacent to the West Clump, a reef (and seal resting spot) off West Harbor.
This sail is 725 square feet and I have it rigged with a dousing sock. As a singlehander when setting or dousing I play the role of a one armed paper hanger, but it is doable if you have all the lines laid out correctly and blanket the sail with the main when setting or dousing. This allows you to continue on a steady course while blanketing the spinnaker to allow the dousing sock to contain a partially collapsed sail. Of course you kneed the assistance of an autopilot, or in this case, I was using my wind vane to maintain a steady course.
As a side note my sheets are dyneema cored and I have removed several feet of the cover, thus exposing the dyneema core which is attached to the clew using a soft shackle. This saves a lot of weight and improves performance in light airs. You can see in the photo that the dyneema core section of the sheet is attached to the clew and the winch has only the covered section of the sheet wrapped around the drum.

Double click on the image to expand it for detail.

[John Stone]

Very nice photo and description Jim. Those are the days we live for. Is that a typo...your asymmetric kite really 725 sf? My 140% tri radial drifter is 616sf and it's huge. My P is 41' and J is almost 18'.
Just curious about that.

[Jim Walsh]

The I is 41, the P is 35, and the J is 13.5 with total of 724 square feet of sail area. Those dimensions are rig dimensions of course so I don’t know the luff, leach, and foot dimensions of the sail itself. I just checked the specifications on the Doyle invoice. I presumed it was accurate.

[John Stone]

The I is 41, the P is 35, and the J is 13.5 with total of 724 square feet of sail area. Those dimensions are rig dimensions of course so I don’t know the luff, leach, and foot dimensions of the sail itself. I just checked the specifications on the Doyle invoice. I presumed it was accurate.
IMG_0437.jpeg

Maybe it is that big. But your combined total sail area (main and 100 percent jib) is around 500sf. So it would be almost 50 percent more. My total SA is about 740. But, your sail also has a nice projecting luff and leach so maybe so.... Either way it's a beautiful sail.

[Jim Walsh]

The I is 41, the P is 35, and the J is 13.5 with total of 724 square feet of sail area. Those dimensions are rig dimensions of course so I don’t know the luff, leach, and foot dimensions of the sail itself. I just checked the specifications on the Doyle invoice. I presumed it was accurate.
IMG_0437.jpeg

Maybe it is that big. But your combined total sail area (main and 100 percent jib) is around 500sf. So it would be almost 50 percent more. My total SA is about 740. But, your sail also has a nice projecting luff and leach so maybe so.... Either way it's a beautiful sail.

When I ordered new sails years ago the stated sail areas were; main 221, staysail 107, large yankee 285, totaling 613 square feet. My standard yankee is clearly smaller than the large yankee but I’m not sure of its square footage, perhaps 180 square feet. The main, staysail, and standard yankee therefore are approximately 508 square feet.
The standard yankee is my early and late season headsail and the large yankee is flown the rest of the season. This combination has worked well for me for several years. After two seasons with the asymmetrical I wish I’d added it sooner. For those times conditions favor its use it’s fantastic.

[John Stone]

When I ordered new sails years ago the stated sail areas were; main 221, staysail 107, large yankee 285, totaling 613 square feet. My standard yankee is clearly smaller than the large yankee but I’m not sure of its square footage, perhaps 180 square feet. The main, staysail, and standard yankee therefore are approximately 508 square feet.
The standard yankee is my early and late season headsail and the large yankee is flown the rest of the season. This combination has worked well for me for several years. After two seasons with the asymmetrical I wish I’d added it sooner. For those times conditions favor its use it’s fantastic.

Right. But usually when reference is made to sail area it's the main plus 100 percent of the fore triangle. For example for a stock CD 36 it's 622. The far reach with the taller rig and longer bow sprit is 779. But if I include the larger staysail it's 963 SF.

I have always understood SA/D is calculated on mainsail ares and 100 percent fore triangle--along with displacement based on full water tanks and fuel tank but no other stores or equipment. I think that formula is used so there is some consistency when comparing boats otherwise we get into to calculations using huge overlapping headsails and the figures have no value.

I mention this only to reference the 500sf comment regarding SA for the CD 31.