What is the purpose of a heaving line?

A heaving line is specifically designed for the purpose of being thrown lightweight across distances, such as from a ship to a pier or between vessels. The lightweight nature of the line makes it easier to throw, allowing for quick and efficient transfers of heavier lines, such as docking or mooring lines, once the heaving line is successfully caught. This function is particularly important during operations in tight spaces or in various weather conditions where precise handling of heavier lines might be challenging.

The other options may describe functions associated with various types of lines or equipment on a ship, but they do not accurately reflect the primary role of a heaving line. For instance, while the monkey fist may use a heaving line for weight, that is not its main function. Similarly, securing lines or reinforcing mooring lines involves different equipment and techniques that do not pertain to the specific utility of a heaving line in ship operations.