... measuring what you have with calipers is the best way to replace with what you have. Determining the line size for a given application takes a bit of calculation but in the end, you'll probably not be happy with the size because it will be smaller than you think. Does that make sense?

We keep Samson's Line Selection Guide on our web site here; http://www.americanriggingsupply.com/index_files/Samson_MarineLine_Selection.pdf

I hope it helps...