ALL KINDS OF ROPES ARE USED AT SEA, from thin twines and yarns to thick hawsers. Synthetic fibers have been developed specifically for use at sea. Nylon ropes stretch, and so are ideal
for anchoring; polyester (frequently called by the trade name Dacron) has little stretch, so is ideal for halyards and sheets. Different knots have different uses. Knots that join two ropes are called bends; hitches join a rope to another object; and bowlines produce an eye (loop) in the end of a rope. Ropes can be joined by splicing (unraveling the ends and weaving them together) or seizing (lashing the ropes together side by side).
