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“I’ve never been able to understand why so many builders and designers use stainless
underwater fittings, fasteners, and hardware. The pitting corrosion problem seems
forgotten or unknown but can be very serious.”
Dave Gerr
Want to know how to prevent this problem? See Metal Corrosion in Boats page 25.
It appears to me that the angled-down large lift strakes be-
ing further apart forward than aft, are ramming water pres-
sure into the suction area aft of amidships.
Back in the Pacemaker days, I wanted to measure the de-
flection of the fiberglass bottom between the stringers aft of
the engines. Pop made me a straight edge with a dial indica-
tor on it measuring in thousandths of an inch. To my sur-
prise when the Captain opened the throttles, the bottom
instead of deflecting upward sucked down.
Lindsey Lord writes in the
Naval Architecture of Planing
, that a constant section of deadrise will relieve this
suction. I disagree. The theory is that the twisting of the wa-
ter under a boat as it travels aft, absorbs power. I believe the
water does not travel aft parallel to the centerline, but fans
outboard toward the chines. The downward-slanting large lift
strakes keep lots of the water traveling parallel to the cen-
terline, thus relieving the suction. Why else would this de-
sign have such a large percentage of resistance reduction
compared to conventional designs? Take a look at the plot
of these boats on George Crouch’s chart. [See page 26 of
September 2010 issue of
The Masthead
Tunnels combined with bubbles and a larger than usual
shaft angle allow these conventional drive engines to be
located farther aft than most competitive installations. This
extra fore-and-aft room allows a large master stateroom and
a utility room under the house floor. Both boats are avail-
able with either an enclosed bridge or an open bridge. There
is a stairway in the house up to the enclosed bridge.
When we first went with the enclosed bridge, none of us at
Ocean realized how popular it would be. Everybody loves the
quietness of the enclosed bridge and the fact that it is air/
conditioned. I would love to have the go-ahead to stretch the
73 to 80 feet. The superstructure and layout could remain
the same. The entire eight feet could be put into a longer
balcony. The engines could move far enough aft to come out
hatches in the balcony. The additional eight feet of length
below decks could be designed to house a belly full of ta
This would give the range to go from Bermuda to the Azo
After that she would have the range to penetrate well int
the Mediterranean.
It would have a new, but similar layout that would fit be-
tween watertight bulkheads with watertight doors. The
crew’s quarters would be aft of the master stateroom, ac
cessible from a stairway from the house, which would als
access the master stateroom. The whole design would a
here to the Coast-Guard requirements for an L vessel taki
passengers for hire, including conformity with requireme
for surviving flooded compartments and damaged stabili
These were to be backed up by calculations that would n
approval by Coast-Guard plan review. There should be an
adequate 110-volt generator aft of the bridge bulkhead f
emergencies. Her engines should perhaps be naturally as
rated crew-boat rated engines, which would reduce strain
moving parts.
She should have a dry-stack exhaust so that if she should
have a flooded compartment, the water could not get int
the engine as it would with a stern exhaust several feet u
derwater in the damaged condition.
In 1910 my father was head of machinery for the South J
sey Yacht Building Company, in Atlantic City. He installed
and serviced the engines in the 40-ft. Tom Bowe’s design
won the Atlantic City to Bermuda rac
1911, 1912, and 1913. How many boats today, 95 years
later, have engines as dependable as those he installed
maintained in the
to purchase the complete
Book of Da
Martin Designs
on CD, from