Notify of
Inline Feedbacks
View all comments
Rob Thompson

That’s very true. To flesh that out with some numbers FYI, our 50 foot performance designed cat has an immersion rate of about 300 kg/cm, or for the metrically challenged, about 1,650 pounds per inch of sinkage. So from our DWL light displacement we only have about 3 inches of additional immersion before the wetted surface increase will start to cause light air performance to drop off due to hull parasitic drag.
And our hull design, particularly the stern “hydrodynamic exit flow” is pretty slippery, so for the charter cats that have what I call bathtub hull shapes, it is much, much worse. Sure, they can carry alot of gear, but need correspondingly bigger rigs and sail plan to be able to sail at all. And when the winds are below about 10 knots, they’re burning diesel.