The raw material for Spectra is Polyethylene which is changed on a molecular
basis and in addition is stretched molecule chains increase the breaking
load and decrease elongation. Spectra has a very low specific weight
and is therfore buoyant. The only disadvantage is that the line creeps,
which shows as the line is elongated under load. Spectra is the most
widely used high-tech fiber in yachting ropes and can be used for all
value-added products such as sheets, halyards and trim lines.