Tad,

We just added a spin this past spring to our 6.0. Its been great and at the same time frustrating. Our spin is in that 400 – 425 range, pic attached. Here are its dimensions:

Luff: 30-9½”; Foot: 19-½”; Leach: 25-8”; Mid Girth: 15’

NE Spin (350 sq ft):
Luff Length 32’-0”
Leach Length 26’-8 1/2”
Foot Length 17’-3 1/2”
Mid-Girth Width 13’-10”
Mid-Girth Width (minimum) 13’-4”

We set up our halyard hoist 28’ from the bottom of the mast. It looks like a masthead but it is not. Our pole is 14’ long and our mast rake is moderate, don’t have a specific measurement. It’s not raked all the way back. Our bow foil is at the standard height.

How do you know that you don’t have enough luff tension?
I have learned from some other sailors in our club and from a little experience now that usually we were sailing the spin with too much luff tension, especially, in the 0-5 and even in the 5-10 range. In 0-5 let off the tack line a foot. If you have a one-halyard/tack line like we have, then let off the halyard a foot. Watch the shape of the luff, it will be come flatter, and you will be able to head higher. One afternoon with a local sail maker on board that was checking out the shape the new main and jib he made for us, I asked him about spin luff tension. I got a clinic about spin luff tension and trimming. Wind was about 6-8 and he let off the halyard/tack line about 3’. That spin became very flat. The more luff tension the rounder the entry. Let it off; let it take a natural shape.

Heading as high as the I-20s? I think you find this difficult to do, we have. We just sail slightly deeper. We combine crew weight and heading to get the hull flying and then just sail our own race.

Spin trim? Just like on the mono-hull with symmetrical spins, sail the curl. However, unlike on the monohull, in order to get the pole in the right position the heading of the boat has to change. I have found the tell tails are only good for the helm to know when the chute is way over trimmed or the boat needs to head up. On 5 and above nights, if the spin is over trimmed, our boat won‘t head up, way too much lee-helm. It has often been heard on our little ship “easy that GDT so I can head up!” It has become a little bit better by leaving the main traveler centered and only easing the main sheet a foot or two.

We were gaining on almost all of the non-spin boats only to loss it back getting the GDT back on board. Snuff has helped greatly with this. However, the bow foil causes some snagging.

Gotta go,

Attached Files
38977-DSCN1369.JPG (103 downloads)

Chris Allen
Nacra 20 Gertie
www.wrcra.org