The heaving line should be ______________ to make it more flexible and less susceptible to becoming tangled.

The heaving line should be braided to enhance its flexibility and reduce the likelihood of tangling. Braiding incorporates multiple strands in a way that creates a more flexible structure compared to other types of construction, such as twisted lines. This flexibility allows the line to move more freely when thrown or handled, making it easier for crew members to manage during operations. Additionally, a braided line tends to have a smoother surface, which helps in reducing friction and snagging on obstacles, further decreasing the chances of tangling during use.

In comparison, shortening the line does not inherently improve its manageability, while coiling can introduce tangling issues if not done properly. Knots, although useful for securing the line, do not contribute to the line's flexibility and can even create points where tangling can occur. Therefore, braiding is the best choice for maintaining a well-functioning heaving line that meets the operational needs effectively.