Stillwater fishing on lakes and reservoirs, especially if you’re in a competition, requires the use of different types of line ( floating, midge-tip, intermediate and sinking). Over the years Marryat designers have discussed these variables with many fishermen who all faced similar problems – how to switch between floating and sinking lines with the same rod and still be able to cast effectively ...
In Theory floating lines have specified weights determining their AFTM number and this specific weight is calculated on the front 30 feet of line. Therefore 30 feet of a 7-weight line must weigh 12 grams and an 8-weight must weigh 13.5 grams, so there’s just 1.5 grams to differentiate them. Now consider that 7-weight rods are designed to work with a line weight of between 11.5 grams and 12.5 grams.
The Challenge here is "my cast collapses when using a sinking line” and these days this also happens with floating lines like Airflo’s Forty-Plus, because their heads are heavier than their AFTM specification. Another consideration is that many fishermen shoot 35 to 45 feet of line these days ... that’s more than 15 grams on a 7-weight line or 30 feet of a 9-weight floating line ... so should you be using a 9-weight rod? No, because if you did you wouldn’t get the first 3 feet of line out.
Marryat's solution is that the designers have created a major innovation, two superb 9 foot 6 inch rods specifically for use on stillwaters with floating and sinking lines. The 7-weight is available in two versions; one designed for use with a Floating Line and, because of the extensive use of heavy-weight floating and sinking lines the other has been developed for SinkingLine (S3 to S7), enabling you to cast heavy lines with confidence.