Deck General · Cordage & Line
Polyester (Dacron) line is preferred over nylon for running rigging and sheets primarily because it:
- AFloats if it goes over the side
- BHas minimal stretch, maintaining sail trim under load✓ Correct
- CResists ultraviolet light better than any other synthetic
- DHas greater breaking strength per diameter than nylon
Explanation
Polyester/Dacron has very low elongation (about 3-5%), so sheets and halyards hold their set position under load without continuously trimming. Nylon's high stretch is a disadvantage in running rigging. Neither floats reliably; nylon generally has higher tensile strength per diameter.
Authority: Deck Seamanship (USCG deck topic)
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