Professional BoatBuilder - February-March 2018

58 PROFESSIONAL BOATBUILDER

RIG DESIGN: Fractional Update

not as close-winded as usual, but the

larger foresail was sheeted outside the

lower shrouds. A er crossing the river

we tacked and sailed back as before,

arriving nearly at the can from whence

we had started. We had made virtually

no distance to windward. Only a er

furling the near-masthead drifter/

taken from the chase boat that joined

us at Maple Juice Cove. Departing

from the mouth of the cove we headed

easterly across the river at slack tide

sailing at about 2 to 3 knots.  e

apparent wind, also 2 to 3 knots, was

at about 40° as indicated on the mast-

head windvane’s display.  is seemed

On the subject of lead—de ned as

the distance the rig’s nominal center

of effort is forward of the hull’s cen-

ter of lateral plane, measured as a

percentage of the LWL—Petrel exhib-

its a particular insensitivity in matters

of balance. While Petrel’s lead is in

agreement with the usual rule-of-

thumb and even though the mast is

well a at station 4, she handles rea-

sonably well under either main or jib

alone, although we rarely do so unless

sailing with just the main in a

crowded anchorage.

____)____

One truly remarkable aspect of

Petrel’s sailing performance occurred

during one of her  rst year’s sailing tri-

als, in Maine’s St. George River in very

light air with the dri er/reacher set.

While I neglected to record any data

that day, what happened is still vivid in

my memory and in the photographs

Demonstrating her ability under main alone, Petrel

sails on the wind back to her mooring in 0 to 2 knots

of breeze. With her shallow, full keel and long-chord

centerboard, she performs in a similar fashion under

jib alone. In both cases, she sails with a higher than

normal apparent wind angle of 35° to 40°.

CHRISTINE SMITH

CABOT LYMAN

Sailing Petrel in very light air (2–3 knots apparent) with the drifter/reacher  ying

and 2–3 knots boat speed, the author could not make any progress to windward

even though the apparent wind angle was about 40°. The true wind angle must

have been about 90°.

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