A day signal, also known as a daylight signal or a signal ball, is a visual indicator used for communication and navigation during the daytime. It is typically a large spherical object that is brightly colored and easily visible from a distance. Day signals are commonly used in maritime operations to convey messages and indicate the status or intentions of a vessel.
One common example of a day signal is the signal ball or ball-shaped day shape, which is hoisted to indicate that a vessel is at anchor. The signal ball is usually black in color and is hoisted in a prominent position on the vessel, such as from the forward mast. It serves as a visual warning to other vessels that the vessel displaying the signal ball is not in motion and is anchored in place.
Day signals can also be used to communicate other messages, such as indicating restricted maneuverability, signaling distress, or conveying other specific information as defined by international maritime regulations.
It’s important to note that the specific meanings and usage of day signals may vary depending on the jurisdiction and the applicable maritime rules and regulations.