SYMMETRIC HULLED CATAMARANS
Planing craft hydrodynamic technology is based primarily
upon experimental data obtained from tests of prismatic planing
surfaces and results of hull series tests. This technology
has been synthesized into simplified empirical equations which
are easily used in design.
The lift on the planing surface is attributed to two
separate effects. One is the positive dynamic reaction
of the fluid against the moving bottom, and the
second is the so called buoyant contribution which is associated
with the static pressures corresponding to the given draft
and trim. At very low speeds, the buoyant lift predominates,
whilst at high speed, the dynamic contribution predominates.
The symmetric hulled catamaran, as developed in Australia,
specifically for operation in breaking surf and rough water
conditions, introduces yet another equation into the hydrodynamic
calculation, that being the dynamic interaction within the
closed tunnel, between the hull surface, and the encapsulated
Obviously, if a hydrodynamic lift can be generated
that exceeds the hydrodynamic drag created by the additional
wetted surface, the resultant additional lift will improve
the drag/lift ratio for given trim angles, enhancing the planing
speed for given power ratios.
Perfection Boats is an American corporation, dedicated
to the further extrapolation and development of the designs
generated in Australia, which is predominant in the technology
at this time.
We have gathered performance data, both analytic
and physical from all major manufacturers of such boats in
Australia, together with model tank test results, and full
scale data collected within the United States. The enclosed
computer enhancement was developed for us by one of the leading
laboratories in the field in the United States, Design Systems
As a result of the cross-pollination of the smooth
water design and the known operating parameters of sea stand
wind strength, we have designed a planing hull sea keeping
technology, with balanced relations between hull form, loading,
speed/length ratio, sea state, and the expected added resistance,
motions, and most importantly, wave impact accelerations.
The results of this development are shown graphically in the
computer generated hull form analysis, color photographs
which are included in this material.
Our catamarans are of the very latest design
and are predictably superior in overall performance and sea-keeping
than any existing catamaran in operation in your geographic
The new generation of catamarans are constructed with
the highest quality components resulting in lighter weight,