Now, although a rod may be designed with a certain species of fish in mind, there’s
actually not such thing as a trout rod, or a bass rod, rather rods that are designed for
certain size fly lines. There’s also really not such a thing as a trout fly line, a bass fly line
or a sailfish fly line as such. If you rely only on species of fish designations, other things
you should consider may be overlooked. For example, you can fish for bass or trout will a
sinking fly line or a floating fly line. You can fish for either species with a Spey fly line
(one specifically designed for Spey Rods) or a regular fly line.
Also, there’s really not any difference in a saltwater fly line and a freshwater fly line. Most
all fly lines can be used in either type of water so such designations alone, are worthless.
Contrary to what you may think off hand, floating lines are not just used with flies that are
fished on the surface of the water. They can be used with wet or sinking flies in certain
situations. Wet flies sink due to their own weight and floating line can be used as a float
to present the wet fly at various depths.
Sinking lines have a higher density than floating lines and sink throughout their length.
The sink rate is usually designated in “inches per second”. Deep water and/or strong
currents require faster sinking lines.
There is also what is called “sinking tip” lines, which have fifteen, or so feet of sinking line
on the end of a floating line. Casting these are not as difficult as casting a pure sinking
line.
Some manufacturers designate their fly lines as tarpon, bass, trout, etc. fly lines but that
is just another designation or name for a certain type of taper configuration that works
well for that particular species of fish. Most of these fly lines will also work well for other
species of fish that you would catch on the same size flies or fishing with the same length,
action, weight, etc fly rod.
As explained later in this series of articles on fly lines, you shouldn’t purchase a fly line
strictly based on the name of the fly line if it is designated for a particular species of fish.
It’s more important to make sure the fly line is the type you want for the fly rod and the
flies you want to cast.