Frenchie / Mary

Probably you are both right. Frenchie refers to flat water, no current, ideal conditions, design limits; while Mary refers to outright instananeous speed and average course speed.

Note that with waves and current help, any boat can surpass its theoretical speed limit. Also, in a burst the limit may not apply. Suppose a tornado (not the boat, the storm) hits a cat. It will fly at incredible speeds. If the storm carries a person, he will brake man's (women's) natural speed limits too.

That said, the key points to check are:

Instantaneous speed x speed over a given distance
Flat sea x favorable waves
No current x favourable current

Personally, I believe that Frenchie is right - and that wave, current and microbursts may have caused some exceptional records (as Mary pointed out) that do not conflict with the limits.

This all standing for standard beach cats - without foils. With foils, the figures are higher.

Something else - maybe Frenchie is not familiar with the ARC 27 and 30 "beach cats", which easily surpass his calculated figures due to their size and excelent engineering.

In any case, beach cats are the fastest cheapest clean way to sail.

Cheers,