USCG Exam PracticeKnots, Bends, and Hitches
A vessel's crew is selecting line for use as a dock line. Polypropylene is available, as is nylon. Which of the following statements provides the most accurate basis for choosing nylon over polypropylene for this application?
- A. Nylon floats, making it safer around propellers than polypropylene.
- ✓ Nylon has higher strength and superior shock absorption compared to polypropylene, despite losing some strength when wet.Correct
- C. Polypropylene breaks down under UV exposure and has lower strength, but its buoyancy makes it preferable for dock lines.
- D. Nylon is preferred because it does not stretch under load, reducing wear on cleats and chocks.
Why B is correct
The Boatswain's Manual states nylon has high strength and excellent shock absorption, making it the most common dock and anchor line. Polypropylene floats (not nylon), has lower strength, and breaks down under UV exposure. Nylon does stretch under load — that stretch is a feature, not a deficiency, for dock lines — but the question asks for the basis for choosing nylon over polypropylene, which is its superior strength and shock absorption.