Nautical Equipment · Day Signals
BLACK BALL NET 610MM 370581
Black net ball day shape, 610 mm. COLREG Annex I size rule, which signals use balls (anchor, NUC, RAM, aground), how many to order.
What it is
IMPA 370581 is a black ball day shape, 610 mm (24 in) in diameter, made of net, unit PCS.
Shapes are the daytime signals of the collision regulations: the rules on shapes apply by day, in all weathers. A ball shows a ship at anchor, two balls a ship not under command, three balls a ship aground.[1]
How to specify and order it
Order enough balls for every signal the ship may need to show at once. One ball is shown in the fore part at anchor (Rule 30). Two balls in a vertical line show not under command (Rule 27(a)). A ship restricted in her ability to manoeuvre shows ball, diamond, ball (Rule 27(b)), and at anchor adds the anchor ball. A ship aground shows three balls (Rule 30(d)). A dredger or a ship on underwater work with an obstruction adds two balls on the obstructed side (Rule 27(d)).[1]
The other shapes are separate codes in the same group: cylinder 370582 (constrained by draught), cone 370583, double cone 370584 (two cones apex to apex, for a fishing vessel) and diamond 370585. A diamond is two cones with a common base, so it is not the same as the double cone.[1]
State net on the order if you want this item, and ask the supplier what the net and the frame are made of and how the shape folds for stowage.
Rules and approvals
COLREG Annex I, section 6: shapes shall be black, and a ball shall have a diameter of not less than 0.6 metre. The vertical distance between shapes shall be at least 1.5 metres. A 610 mm ball meets the 0.6 m minimum. Vessels under 20 metres may use smaller shapes in proportion to their size, with the spacing reduced to match.[1]
Annex I, section 14: the construction of lights and shapes shall be to the satisfaction of the flag State. Some exemptions apply by size: a vessel under 7 metres at anchor away from channels and anchorages, and a vessel under 12 metres aground, need not show the shapes of Rule 30.[1]
Questions buyers ask
- What size must a day signal ball be?
- Black, at least 0.6 metre in diameter under COLREG Annex I, with shapes at least 1.5 metres apart. Vessels under 20 metres may use smaller shapes in proportion.
- How many black balls does a ship need?
- Enough for the signals it may show at once: one at anchor, two when not under command, two (with a diamond) when restricted in ability to manoeuvre, three when aground.
Sources
No prices: offers come from suppliers at the port.
Published by Sherif Awad, founder of GeoMarineHub — in ship supply since 1990, a family business since 1981 (45 years). Last checked .
Specification · IMPA 370581
Read off the catalogue name · priced per piece
- IMPA code
- 370581
- Unit
- PCS
- Size
- 610 mm
- Colour
- black
Also in Day Signals
| 370582 | BLACK CYLINDRICAL, SHAPE NET 610MM | PCS |
| 370583 | BLACK CONICAL, SHAPE NET 610MM | PCS |
| 370584 | DOUBLE CONICAL, SHAPE NET 610MM | PCS |
| 370585 | DIAMOND SHAPE NET 610MM | PCS |
Requests by e-mail · no account needed
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