Skagit vs. Scandi...
Skagit (wet flies/sink tips) heads offer the ability to fish larger heavier flies which require sink tips. It is possible to fish small dry flies or soft hackles on a skagit head, just a little less finesse.
Scandi (dry flies and small soft hackles) heads offer a more delicate presentation and are used for skating dry flies and soft hackles just beneath the surface.
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OPST vs. Orvis Mission. A major grain difference what's going on?
OPST threw the skagit head industry a curve ball when Ed Ward and Jerry French collaborated on a whole new methodology when it came to designing skagit lines.
OPST heads are lighter and therefore 40 to 60 grains less than the rest of the industry.
So how did they do it and which is right for you.....
Skagit Head Formula
#1 It takes mass to move mass - Weight aka Grains
#2 Kinetic energy - Velcro Effect or Line Stick
Designing the perfect skagit is a delicate balance between these two elements.
OPST took the unique and wholly original approach of the "velcro effect."
OPST has designed a wider head which means a larger surface area must be peeled off of the water in order to execute the cast.
Feel. OPST vs Orvis Mission
OPST heads will feel lighter when casting. Most folks who began using heavier heads go through an adjustment period and may tend to find initially over line their rods by 25 grains though eventually dial things back as they adjust.
Mission Heads will be easier for most folks to adopt if they have some prior spey casting experience. They will load deeper into the rod and have an easier time punching through the wind due to the greater weight or grains.