Saturday, May 01, 2010
science behind skagit casting - Skagit Double Spey
Skagit double spey casting probably is the most interesting cast I have ever seen and learned. It is such a wonderful cast to pull out the heavy sink tip and heavy fly. Just thought it might be a good idea to provide some thoughts here and illustrate what I think about Skagit casting style and sustain anchor concept. (I don’t want to bore anyone here with physics… I will avoid scientific terms and try to use more interesting videos to illustrate my thoughts) (I apologize if some of you not like seeing physics)
First off, not to be confused by the Traditional Double Spey (TDS). The video provide here demonstrate the casting movement of Skagit Double Spey (SDS) Video LINK
As Ed showing in his video and this clip (start from 0:18 sec). There are several distinct characters of SDS compare to the TDS.
1. More circular movement : In the video clip (start from 0:18 sec) you can see a distinct and exaggerated circular movement of SDS casting (almost a full circle - 360 degree). Ed has describe this like “Olympic hammer thrower”, the circular movement of the line not only grab the water tension liner but also circular to maximize the rod load. Indeed, by placing the anchor “so close to center of casting”, the line actually “spin and pull outward” that centered on the heavy tip and heavy fly. In the video, Ed has described the heavier the sink tip and fly, the more horizontally you position the rod. This will increase the sweep radius thus maximized the angular momentum to begin with (see below for detail). Like all the figure skiers, start with the open arms then close the arms to increase the spinning speed without adding any other forces (the conservative law of angular momentum: see Video LINK) Video2. At the end of the sweep, the 45 degree thrust naturally close up the sweep radius and increase the line speed dramatically, thus load the rod even more in the casting fire position.
2. Take an advantage of heavy tip and heavy fly: The cool thing about the SDS movement is actually SDS “embrace” a heavy tip and heavy fly as friends and work with them. They are no longer a hazard factor in spey casting, but essentially become a helper (sustain anchor) in the SDS casting. The heavier the tip, the more power move you can do to on hold “the load” into the rod sweep without blow the anchor. For this point of view, I think SDS casting really set itself apart from other spey casting styles (touch and go).
3. Use circular plane to control the power: slowly and more controllable way to cast. TDS use speed to control the power, but in SDS casting, you actually can use "the circle plane" to control the power. You can use all casts with the same sweep speed to cast different tip (include floaters) by position the rod tip in different plane of height (as demonstrated in the Skagit Master video). This is the use of angular momentum law again. Under the same sweep speed, the wider the radius in the sweep the more energy will be released in the final casting stroke. Smaller radius for dry tip, bigger(more horizontally) radius for the heavy tips.
For the reasons listed above, in my humble opinion, Skgit casting in not just a special line configuration to deliver a heavy tip and fly, but also has it distinct casting style (at least in SDS casting) to uses and take advantage of the sustain anchor.