I am about to replace the halyards and sheets on my 25' sailboat. I have
measured the old lines with a caliper, and had my neighbor repeat the
measurements to be sure they were consistent. The result is that the lines
measure between 5/16 and 3/8 for the halyards, and between 3/8 and 7/16 for
the sheets.

Does anyone know if old, weathered lines tend to measure more or less than
their nominal diameter? I.e., are these 5/16, 3/8 or 7/16?

BS