JANUARY 20, 2026
THE DEFINITION OF “LIGHT
AND VARIABLE WIND”
Predictions for wind were dismal, and the limp flags
confirmed the forecast. It looked so weak
that some boats opted to not come out.
As we left the harbor around 2pm there was a breeze developing by the
wharf and we had a break in the predominant heavy cloud cover. As the clock ticked down, there was a mild
5-6 knot breeze. The wind was coming from
240 degrees, so we decided to set an offset mark about a quarter mile roughly
upwind and called for a course of: S/F>offset mark>Mile>S/F. We blew the five-minute horn which seemed to
be a signal for the wind gods to go back to sleep. We had 9 boats out for the drift-fest. At the
start, boats were drifting across the start line in a 3-4 knot breeze. Fortunately, as we sailed further out, the
wind seemed to increase with close to 9 knots as we approached Mile. As we
rounded Mile, the wind died and the
finish at S/F seemed out of reach as most boats bobbed with no forward movement.
Despite the curse of no wind, 3 boats actually finished the
complete course. I offered the option of
taking the finish time at Mile so everyone could stop bobbing. The first boat to round Mile was Flexi Flyer,
then Aboriginal. Though Main Squeeze sailed
and finished the long course, their track froze so I could not report a finish
time for them. The afternoon sail was a
definition of “Light and Variable wind”.

Jennifer Kinsman photo of the drift-fest
The track for this afternoon can be reviewed at:
https://www.regattahero.com/mapviewer/?organisation=scyc&passcode=233793®atta=Tues%20Fleet%20B&race=20.1.2026%2015:00:00&language=en&defaultspeed=5&loop=no
PHRF ADJUSTED RESULTS : SHORT COURSE: FINISH AT MILE COURSE
DIST .965NM
PLACE BOAT PHRF ET CORRECTED
1 FLEXI FLYER 96 19:05 17:32
2 ABORIGINAL 33 19:12 18:40
3 PERFECT 36 144 25:06 22:47
4 AVATAR 132 25:03 22:56
4 ROSIE 162 25:33 22:56 (TIE)
6 AQUAVIT 72 24:10 23:01
7 SAILING PAIR
A DICE 180 27:15 24:21
8 SAGITTARIUS 120 26:25 24:29
LONG COURSE FINISHERS:
COURSE LENGTH 1.930NM
1 ABORIGINAL 33 46:17 45:13
2 FLEXI
FLYER 96 52:26 49:21
Next Tuesday will be the last
Tuesday of the month and we are back on track to have our end of month
BARBECUE. Bring your best grilling food
to cook and share. Pray for fair winds
and good weather!
ZOOP
SCOOP BY PAUL TARA
PRISM SENTENCES
In
geometry, a prism is a 3 dimensional solid shape, with flat, parallel, polygonal
ends connected by parallel sides. A simple example would be the edges of
a straight 2 x 4, with parallel ends. In yacht design, aside from length,
beam, and draft, the prismatic coefficient, or Cp, may be the
one of the most descriptive statistics when it comes to hull shape. It
basically represents how tapered the ends are, as a ratio, relative to the
hull’s largest underwater cross section. A vessel with no change in shape
from bow to stern, like a barge (or an un-tapered 2 x 4), has a Cp of 1, or
close to it. The more tapered the shape is at the ends, the lower the
number.
Like
wetted surface, Cp is difficult to calculate unless you have lines and a CAD
program. For many designs it’s proprietary. But, just roughly, sailboats with
low numbers tend to have finer ends, more rocker, less wetted surface, and
lower top speeds. Those with higher numbers have fuller ends, less
rocker, more wetted surface, and higher top speeds. For example, the Cp of
a SC50 is around .56, while those of similar sized IOR designs could be
down in the low .50’s. That’s because Cp is a hull-speed indicator, and
lowering it by pinching the ends produced lower ratings. Then, there’s the
tricky part, depending on its shape, a yacht’s Cp can change dramatically as it
heels (scow bow anyone?).
Modern
performance designs, like sprit-polers and, now, foilers, have very high Cp’s,
edging towards .60. The further apart a designer can push the crests of a
hull’s bow and stern waves, the faster her “wave train” travels. (Think of a
super tanker, where the crest of the bow wave is often ahead of the hull
itself.) For a given length, the higher the Cp, the longer the wavelength,
resulting in a higher hull-speed, The higher the hull speed, the sooner a boat
can achieve her planing or foiling speed. Once that threshold is crossed,
theoretical speed limits go out the window..
If
you want to view examples of prismatic extremes, just pay a visit to the Club’s
Junior Yard, where Optimists and El Toros are stored side by side. Although
both designs have hard chines, Optimists are ‘bricks’ with flat bottoms, and
little rocker, (high Cp) —they are slugs in light air. El Toros are
tapered, with more rocker and more dead-rise (lower Cp) — they’re faster, until
conditions get ‘sporty’ when they become difficult to control. And then, of
course, locally there’s the ultimate light-air speedster, the Jester Dinghy,
which may have the world record lowest Cp.
By
the way, the Club is selling a few of its El Toros. They are
‘well-seasoned’, but you might want to take a look.
Thank you Paul!
I hope to see you sailing next Tuesday and at the BBQ at the
club.
Barry Keeler
Sailing Pair A Dice


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