What shape indicates that an object being towed is longer than 200 meters?

A diamond shape is used to indicate that an object being towed is longer than 200 meters. This is part of the visual signaling system outlined in the COLREGs to help vessels communicate their status and the nature of their operation to others, particularly in conditions where visibility may be limited.

When a vessel displays a diamond shape, it signifies that the length of the tow is significant, thereby informing other vessels to exercise caution and consider the implications for navigation. This visual cue is crucial for maritime safety, ensuring that other vessels are aware of the potential hazards associated with maneuvering near a long tow.

Other shapes do not convey this specific information related to the towing of long objects. For instance, a circle is commonly used for signaling certain types of vessels or activities, a square may indicate different vessel operations or statuses, and a triangle is often associated with specific navigational signals that do not pertain to the size or length of towed objects. Therefore, the diamond shape is distinctly recognized for indicating longer tows, ensuring effective communication on the water.