What function does a cleat primarily serve on a vessel?

A cleat primarily serves to secure lines or ropes on a vessel. This role is crucial for maintaining control and stability, as cleats provide a reliable point to tie off mooring lines, fenders, or halyards. When a vessel is docked or at anchor, proper tie-up with lines secured to cleats ensures that the vessel remains in position, preventing unwanted movement caused by currents, wind, or waves. This securing effect contributes significantly to the safety of the vessel and its crew.

The other functions listed do not align with the primary purpose of a cleat. While propulsion is managed by engines and sails, and anchoring involves the use of anchors and chain, the cleat is specifically designed to hold lines securely. Additionally, marking navigational points is handled by buoys and markers rather than cleats. Understanding the function of a cleat is key for safe and effective vessel handling in various maritime operations.