Originally Posted by derelict
Question: while looking around and getting the stuff, I noticed that there are a lot of spey fly lines. Can you substitute a sinking fly line instead of a running line?
Why would you want to do that?! Having a sinking line that stands in for a "running line" would make mending impossible and shooting extra line at the end of a cast difficult at best.
Modern shooting/running line which has historically been thin monofilament and didn't break the water tension (theoretically) is now being made hollow so that it will float even better.