Ahhhhh 3 strand?
but will look a bit off.
Then again we've just done 2 sets for superboats and those boys know how to spend the coin. And it's all about the looks babe, structural integrity seems not to matter.
16 to 20mm depending on how grunty you want.
2 at 1/2 the length of the boat
, 2 at the length of the boat
and maybe one 1.5 times the length. That's about an 'average' set.