Jarmo Hurri wrote:
equations snipped
So, in my small mind it seems that in order for a 5wt silk line to
have a smaller diameter (lower profile) than an ordinary line, one of
the following must be true:

1. The silk line does not float as well as the ordinary line (because
it has a higher density). ...

I think this is it. A silk line won't float at all unless you
dress it, usually with red Mucilin.

--
Ken Fortenberry