Rule 27. Not under command, restricted in ability to manoeuvre, divers, mine clearance

When the tow leaves the towing and towed vessel almost no room to deviate from their course, the towing lights are joined by all-round red, white, red.

Set

The towing lights of 24 (a) plus all-round red, white, red. Ball, diamond, ball by day.

Tell

Two whites in a column next to three all-round lights: a tug that physically cannot turn.

Priority

Everyone gives way to her except a vessel not under command.

Two all-round red lights in a vertical line. Two balls by day. This is a breakdown: she cannot manoeuvre.

Set

Two all-round reds.

Tell

Two reds in a column and no whites at all: not under command and not making way.

In fog

One prolonged and two short blasts.

Priority

Every vessel gives way to her, without exception.

Sidelights and a sternlight are added to the two all-round reds. Masthead lights are not shown, even while she carries her way.

Set

Two all-round reds, sidelights, sternlight. No masthead lights.

Tell

This is the key fork: a masthead light next to two reds means she is not a breakdown but restricted in ability to manoeuvre, and there the lights are red, white, red.

Causes

Steering gear failure, loss of propulsion, engine breakdown.

All-round red, white, red in a vertical line. With way on she adds masthead lights, sidelights and a sternlight.

Set

All-round red, white, red, masthead lights, sidelights, sternlight. Ball, diamond, ball by day.

Tell

The white in the middle of two reds means work, not a breakdown: cable laying, replenishment underway, launching aircraft, mine clearance, a heavy tow.

In fog

One prolonged and two short blasts.

Priority

Everyone gives way to her except a vessel not under command.

All-round red, white, red plus the anchor lights of rule 30.

Set

All-round red, white, red and the all-round white anchor lights.

Tell

Three all-round lights together with anchor whites: the work is being done from anchor, she is not going anywhere.

In fog

One prolonged and two short blasts instead of the bell.

Two all-round reds mark the side where the obstruction is, two all-round greens the side on which another vessel may pass.

Set

Red, white, red plus two reds on one side and two greens on the other.

How to read

Go where the two greens are. On the side of the two reds there is pipeline, anchors or the dredger's gear.

By day

Ball, diamond, ball plus two balls on the obstructed side and two diamonds on the clear side.

At anchor

These lights replace the anchor lights.

When her size makes the full display of paragraph (d) impracticable: all-round red, white, red and a rigid replica of flag «A» not less than 1 m high.

Set

Three all-round lights and a rigid flag «A» visible all round.

Meaning

There are people in the water. Passing close at speed is dangerous: slow right down and leave room.

Exception

Vessels under 12 m are exempt from rule 27, but not when engaged in diving operations.

Three all-round green lights or three balls in addition to the lights for a power-driven vessel: one near the foremast head, two at the fore yardarm ends.

Set

Power-driven vessel's lights plus three all-round greens in a triangle.

Meaning

It is dangerous to approach within 1000 metres.

By day

Three balls in the same positions.