Fly fishing at the water temperature we have in October (50’s) using the correct fly line wil help you catch the largest bass.
At this time of the year I make sure I carry three different style fly lines in order to fish my flies at the depth required to catch bass at all depths in which they might feed.
1. I use a floating fly line in order to catch them in shallow water and when they feed on the surface.
2. I use a Scientific Anglers Mastery Sink Tip III Fly Line to fish the fast runs and moderately deep water.
3. I use a Teeny 200 Sinking Head Fly Line in order to fish the deepest pools.