Day Shapes are signals raised during daylight hours to indicate their status to other vessels.
The signals consist of geometric shapes, like a sphere, a cylinder, a diamond, and a cone.
When combined together, the shapes communicate different messages: A single ball means "at anchor". An inverted cone means "Under sail & power". A diamond means "towing vessel", or "vessel towed". Two cones with their points touching in the middle means "Fishing with limited maneuvrability", when paired with a single cone it means that there is outlying gear more than 150 M from the vessel. Two balls over one another means "not under command". 3 balls laid horizontally, with the middle ball raised higher, means "minesweeping". 3 balls over each other means "aground". A diamond sitting between two balls vertically means "restricted maneuvrability", it is paired with: 1) 2 diamonds laid vertically over one another, which indicates the safe side to pass the vessel 2) 2 spheres over one another vertically, which indicates the side where the obstruction exists. A vertical cylinder means "constrained by draft". A square over a sphere means "in distress".