Dear Wouter,

The topics surely grew more and more interesting about the "ideal 19 ft cat ".

In fact, you are quite right about the relative importance of hydrodynamic drags. At maximum speed, where the rig propulsive force reachs a top level around 90 lbs ( 12 % of the whole crowded boat ), hull friction drag accounts for 55 to 60% of total drag ( appendages 25% and divergent wave-pressure resistance for less than 20% )...so reduction of wetted area is REALLY the main concern !

About the beam aerodynamic drag, it's more doubtful ! Intensive wind tunnel tests for Ollier's big cats didn't show spectacular levels, the induced vortical drag from the rig is the main aerodynamic component, hull drag with lateral huge separations came after, and beams followed...The water that hits regularily the connexions over the deck bridge is far more critical than aerodynamic fairing ( water has a 800 times superior density !!! )

Sincerely Yours,
Frenchie