Masthead28_Dec2013 H.pub - page 7

The Masthead
Dec. 2013 Page 7
gers comfortable. We also felt that it was necessary to cre-
ate a hull that transitioned to plane effortlessly and could be
controlled throughout the speed range without any notice-
able "hump" by placing the LCG 58% of the WL length.
To keep the construction
light and efficient for a one
-off build, a unique v-bevel
strip planking system was
tested and then used. The
planking method was con-
ceived and refined during
a discussion with a group
of fellow Westlawn
students. A small bevel is
sawn into one edge of all
planking and the planks
are temporarily screwed or
tacked to the male molds.
After all the planking is
secure and fair, an epoxy
grout is pushed into the gap created by the bevel. Because
the planks fit tight on the inside of the boat, the builder was
able to apply a clear finish to the inside of the hull. As was
mentioned, some destruction tests were conducted on sam-
ples of both traditionally edge-glued strips and the v-bevel
planking. In 8 out of 8 test samples, the v-beveled samples
broke along the wood grain and not the glue joint, just as
with the traditional strip planking. The designer had the op-
portunity to assist in the planking process and was
extremely satisfied when the whole boat was planked,
faired, and the exterior fiberglass was applied in three days.
The first launch and sea trials were an exciting time. The
boat floated level on her lines and the new motor started in
an instant. The winds on the Chesapeake Bay on that after-
noon were around 16-20 knots out of the south, so there
was a pretty nasty chop running up the bay. As we had to
follow the instructions for breaking in the motor, we made
our way north to the Severn River and then up to Annapolis
at about a third throttle. When our stopwatch indicated that
we could increase throttle to two thirds RPM, we swung the
bow around and headed directly into the teeth of those 20-
knot wind-created waves.
Immediately, we noticed
how easy it was to keep
her on plane. The most
gratifying moment came
when I aimed for a particu-
larly steep set of waves.
Instinctively, we both
braced for an impact and
drenching that never
came. The boat rode the
first wave and sliced
through the second, while
the flare pushed the spray
aside. I will never forget
when the builder turned to
me and exclaimed, "holy cow, what just happened?" We
spent the rest of the evening searching for waves to see if
we could get wet! I counted only a few drops on my shirt by
the time we returned to the dock. In calmer water, she
reached her calculated
top speed of 27 knots and
cruised quite comfortably
at 20-22 knots in slightly
lumpy waters. The builder
hasn't done an exact
calculation of efficiency at
this point, but estimated
he drove the boat 90
miles on 7 gallons of gas
for an average of almost
13 miles to a gallon. This
coincides with docu-
mented performance bul-
letins published for this
motor on similar craft.
Click
f
or a video of the boat.
Specifications:
LOA: 15 ft. - 9 in.
DWL: 13 ft. - 6 in.
Beam: 6 ft. - 6 in.
Draft (hull): 0 ft. - 7 in.
Draft (outboard): 26”
Power: 40-60 h
Designer:
Kurt Cerny
Cerny Yacht Design
CERNY YACHT DESIGN
USA–MARYLAND
3323 Arundel on the Bay Road
Annapolis, Maryland 21401
PH 410.858.4186
Email
:
Web:
Builder:
Quiet Water
s
Boatworks
Web:
Kurt Cerny has nearly
completed his Westlawn
studies.
Hill 16
(Continued)
1,2,3,4,5,6 8,9,10,11,12,13,14,15,16,17,...40
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