Day shapes

These signals consist of a set of simple geometric shapes—ball, cylinder, cone, and diamond—that are displayed, hung from a mast, in a prescribed manner to indicate a vessel's operational status; some of these signals may be somewhat involved.

[1] The meanings of the shapes are defined by the International Regulations for Preventing Collisions at Sea (ColRegs).

Day shapes are commonly constructed from a light weight frame covered with fabric and are designed to be collapsible for ease of storage.

[4] A square black flag displayed over the ball may be used as a distress signal.

[5] Some of the most common signals (see Day shapes diagram): This article related to water transport is a stub.