Choosing a Spey Line
There is a mind-boggling array of fly lines on the market - all with different names; "Spey", "Skagit", "Scandinavian", for example. Knowing which one to choose for the two-handed spey rod you have is very bewildering. We are here to make it all a little easier to understand.
A good rule of thumb with all types of spey lines is that the shorter the head length, the easier they are to cast. Use your rod length as an indication of "easy". A spey line that has a head 3 times longer than the rod is easier to cast (for example a 12 ft rod with 36 ft head length) than a line with a head that is 5 or 6 times longer than the rod.
Another advantage with shorter head length lines is that you can use them in much more restricted spaces than longer head lines. A long head spey line is more difficult to cast, and needs more space behind the caster, however they are more efficient at fishing (spending less time stripping in line between casts) and are a delight to use (when a caster is good enough).
There are three different types of lines that you will hear talk about: "Spey", "Scandinavian" (usually abbreviated to "Scandi") and "Skagit". Each of these has an advantage over the others in certain situations. If you know what the advantages of each of these groups are, you can choose the type of line you need much more effectively.
The advantage a Spey line has over the Scandinavian and Skagit type lines is versatility. Spey lines are a good choice for anglers that are going to fish in multiple destinations, for a variety of species and in all seasons.
As the name suggests, Scandinavian style heads originated in Scandinavia. They are usually shooting heads with long front tapers, and they are very pleasant to cast. The heads are short - usually no longer than three times the length of the rod, thus they are much easier to cast than Spey lines, and very good for smaller rivers and tight casting situations. The main disadvantages with this type of head is that they don't cast heavy flies and fast sinking tips well, and that there is a lot of fishing time wasted at the end of each cast stripping the line back (if you make along cast!).
Skagit lines/heads are short and heavy - even shorter than Scandinavian lines in most cases; working on a ratio of less than three times the rod length. Skagit lines do need a front tip added (whether floating or sinking) before they are ready to fish. They are the newest design of spey line on the market and the strength of Skagit lines is that they lift weight very easily. Anyone fishing large or heavy flies will find nothing casts these easier than a Skagit line. Likewise, a fast sinking tip is far easier to cast on the end of a Skagit line than either of the other two types. Also, as Skagit heads are so short, they are the easiest of all spey line designs to cast, and certainly the best for the tightest of back casting spaces.
The disadvantage with Skagit lines is that they don't have the same kind of presentation as the other two types, and tend to be clunkier when they land. Because they are so short, they also have a lot of stripping in after each cast has fished out.
The first part of choosing a spey line is always going to be choosing the best taper for the situation you are fishing. Many casters prefer shooting head options so they can interchange between Scandinavian and Skagit heads as they fish different seasons or species, and only need a single reel and a shooting line to do this.