Fly rod action describes the flex in the rod, and how long it takes to recover after the rod is loaded.
Which action is best will depend on the type of fishing you plan on doing. Delicate small stream fishing will require a slow action, and fishing for the larger fish on larger rivers will call for a stiffer, fast-action fly rod.
Trout fly rods of the same weight can have different actions. However, the lighter weight fly rods tend to have a slow action, and the heavier rods tend to have a fast action.
A slow-action rod will bend throughout the length of the rod and is most often used with the lighter weight fly rods.
They are used on smaller streams where casting in close range with a delicate presentation is needed. I have maintained for a long time that small streams are a great place to learn the fly fishing basics.
As the name implies, a slow-action fly rod loads slower, allowing more time to feel the weight of the line. This extra time allows the caster to present the fly in a delicate manner to a wary trout.
Slow-action rods can be helpful in playing the fish because rod flex will help protect light tippets. Learn more about leaders and tippets. These lighter rods are harder to cast when there is a strong wind.
Medium-action rods will load faster and will flex the most in the top 1 / 3 to 1 / 2 of the rod. It is a good action that will meet the needs of the average caster. It is good for casting longer distances.
When you are trout fishing with nymphs you can feel the strike on a medium-action fly rod a lot better than you can with a stiffer, fast-action fly rod.
Fast-action rods flex mostly in the top 1 / 4 to 1 / 3 of the rod. Most 5- to 10-weight fly rods are offered with a fast action.
It is a stiff rod with a strong backbone. This stiffness will put more strain on a light tippet, making it easy to lose a large fish if you are impatient. The stiffer rod will help lift a larger trout out of a deep hole, assuming your tippet can handle the pressure.
You can cast farther and with greater line speed with this fly rod action. This makes it good for windy days. Fast-action rods load fast and require better control and timing. This is why time spent working on your casting skills is important.
For a novice, the action of the rod will not be an important issue. A manufacturer of a rod in the lower to middle price range may not even tell you what the rod action is anyway. Focus on the weight and length of the rod and don’t worry about the action for your first rod.
Ever watch someone give a shake to a fly rod in the showroom?
Ever do it yourself without knowing what you are looking at?
Check out this animation showing the nodal points on a fly rod.