Long thin hulls do not obey the same rules
But how does water know, that the hulls are thin?
I'd be interested to see if you could work out a similar multihull formula
found the formula to calculate wavedrag, with todays computer we can calculate the drag of a boat hull by ourself.
Here are the plots of absolute hull drag [img]
http://www.catsailor.com/gallery/displayimage.php?album=lastupby&cat=0&pos=5[/img]
and in the second picture you see the wave drag contribution to total drag. You can sclae up the speeds with sqrt(LWL), if the boat is four times longer you have to read the value at two times higher speeds. The speed is in m/s with 1 m/s = 2kts.
In short words: Length is important (again), but not as important on heavy and slow monons, because wave drag scales with the finess of the hulls.
Cheers,
Klaus
