Day shapes
Encyclopedia
Day Shapes are mast head signals
indicating the navgation status of a vessel at sea to other vessels.
The meanings of the shapes are defined by the International Regulations for Preventing Collisions at Sea
.
The most common signals are as follows:-
Maritime flag signalling
Maritime flag signalling, generally flaghoist signalling, is the principal means other than radio by which ships communicate to each other or to shore; distinguished from flags showing nationality, ownership, or organizational status...
indicating the navgation status of a vessel at sea to other vessels.
The meanings of the shapes are defined by the International Regulations for Preventing Collisions at Sea
International Regulations for Preventing Collisions at Sea
The International Regulations for Preventing Collisions at Sea 1972 are published by the International Maritime Organization , and set out, inter alia, the "rules of the road" or navigation rules to be followed by ships and other vessels at sea in order to prevent collisions between two or more...
.
The most common signals are as follows:-
| Navigation status | Day shape | Restriction |
|---|---|---|
| Vessel Under Sail & Power | Cone | > 12m |
| Anchored | Ball | > 7m (not in channel) > 20m (in anchorage) |
| Constrained by Draft | Cylinder | |
| Aground | 3 Balls (vert. line) | > 12m |
| Not Under Command | 2 Balls (vert. line) | > 12m |
| Restricted in Ability | 1 Ball+1 Diamond+1 Ball | > 12m (except dive boats) |
| Fishing (commercial) | 2 Cones (vert. line) | > 20m (but must display (nets or trawling) basket shape |
| Vessel Towing | Diamond | Tow > 200m |
| Vessel Being Towed | Diamond | Tow > 200m |