What is the requirement for vessels that are aground in terms of signaling?

Vessels that are aground are required to display specific shapes as part of their signaling to indicate their situation. According to the COLREGs, particularly in the context of vessels that are not underway, displaying a specific configuration of shapes helps communicate their status to nearby vessels, thus enhancing safety on the water.

For instance, displaying two black balls is a recognized signal for a vessel that is aground. This allows other mariners to be alert to the potential hazard and take appropriate action to avoid a collision. The use of shapes is a key method of signaling in maritime contexts, and such visual signals are specifically mandated to ensure that the status of the vessel is clear to others in the area.