Day shapes cheat sheet

At anchor · Rule 30

One ball, forward where it can best be seen. Shown by a vessel at anchor.

Not under command · Rule 27(a)

Two balls in a vertical line. She cannot manoeuvre as the rules require, for example after engine or steering failure.

Restricted in ability to manoeuvre · Rule 27(b)

Ball, diamond, ball. Her work (cable laying, survey, servicing a buoy) limits how she can manoeuvre.

Aground · Rule 30(d)

Three balls in a vertical line.

Constrained by her draught · Rule 28

A cylinder. A power-driven vessel that cannot deviate from her course because of her draught and the depth of water.

Sailing vessel under power · Rule 25(e)

One cone, point down. A yacht with sails up but the engine running is a power-driven vessel.

Engaged in fishing · Rule 26

Two cones, points together. A vessel under 20 m may show a basket instead.

Fishing, gear out more than 150 m · Rule 26(c)

Two cones points together, plus one cone point up in the direction of gear extending more than 150 m horizontally.

Towing, tow longer than 200 m · Rule 24

A diamond, shown by both the towing vessel and the tow when the tow is more than 200 m long.

Dredging, with an obstruction · Rule 27(d)

Restricted-ability shapes, plus two balls on the side where the obstruction is and two diamonds on the side you may pass.

Mine clearance · Rule 27(f)

Three balls: one at the foremast head and one at each end of the fore yard. Keep at least 1000 m clear.