Answer: false. Total head weight and first-30-foot weight are two different measurements, and a manufacturer’s specification can give different values for them. The head is the weighted front section of the line; the first-30-foot figure measures only the first 30 feet of the line. There is no rule that the two numbers have to match.

That matters when you compare lines. A head weight describes the whole head; a 30-foot weight describes a fixed length, and on a line whose head is not exactly 30 feet the two will not agree. Reading one number as if it were the other can make two lines look more alike, or more different, than they are.

If you are matching a line to a rod or comparing two lines, compare like with like: head weight with head weight, 30-foot weight with 30-foot weight. The manufacturer’s listing is the place to check which figure you are being given.

Source

From the Scientific Anglers SONAR Titan sink-tip specification; terms follow the FFI Fly Casting Definitions.