What shapes shall a vessel engaged in dredging or underwater operations exhibit when restricted in her ability to Manoeuvre?

Vessels not under command or restricted in their ability to manoeuvre.

(a) A vessel not under command shall exhibit:

(i) two all-round red lights in a vertical line where they can best be seen;

(ii) two balls or similar shapes in a vertical line where they can best be seen;

(iii) when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight.

(b) A vessel restricted in her ability to manoeuvre, except a vessel engaged in mineclearance operations, shall exhibit:

(i) three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;

(ii) three shapes in a vertical line where they can best be seen. The highest and lowest of these shapes shall be balls and the middle one a diamond;

(iii) when making way through the water, a masthead light or lights, sidelights and a sternlight, in addition to the lights prescribed in sub-paragraph (i);

(iv) When at anchor, in addition to the lights or shapes prescribed in sub-paragraphs (i) and (ii), the light, lights or shape prescribed in Rule 30.

(c) A power-driven vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course shall, in addition to the lights and shapes prescribed in Rule 24 (a), exhibit the lights or shapes prescribed in sub-paragraphs (b) (i) and (ii) of this Rule.

(d) A vessel engaged in dredging or underwater operations, when restricted in her ability to manoeuvre, shall exhibit the lights and shapes prescribed in sub-paragraph(b) (i), (ii) and (iii) of this Rule and shall in addition, when an obstruction exists, exhibit;

(i) two all-round red lights or two balls in a vertical line to indicate the side on which the obstruction exists;

(ii) two all-round green lights or two diamonds in a vertical line to indicate the side on which side a vessel may pass;

(iii) when at anchor the lights or shapes prescribed in this paragraph instead of the lights or shape prescribed in Rule 30.

(e) Whenever the size of a vessel engaged in diving operations makes it impracticable to exhibit all the lights and shapes prescribed in the paragraph (d) of this Rule, the following shall be exhibited;

(i) three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;

(ii) a rigid replica of the International Code Flag "A" not less than 1 metre in height. Measures shall be taken to ensure its all-round visibility.

(f) A vessel engaged in mineclearance operations shall in addition to the lights prescribed for a power-driven vessel in Rule 23 or to the lights or shape prescribed for a vessel at anchor in Rule 30 as appropriate, exhibit three all-round green lights or three balls. One of these lights or shapes shall be exhibited near the foremast head and one at each end of the fore yard. These lights or shapes indicate that it is dangerous for another vessel to approach within 1000 metres of the mineclearance vessel.

(g) Vessels of less than 12 metres in length, except those engaged in diving operations shall not be required to exhibit the lights and shapes prescribed in this Rule.

(h) The signals prescribed in this Rule are not signals of vessels in distress and requiring assistance. Such signals are contained in Annex iv to these Regulations.

Meaning of this Rule.

Sailtrain.co.uk is free to use, but if you feel you would like to contribute to the running and development costs you can donate via Paypal:

Questions and Answers

Rule 27

Vessels not under command or

restricted in their ability to manoeuvre

Q 27-1              Which classes of vessels does Rule 27 considers ?

A 27-1              Rule 27 and Par. 27.1 General

                        Click on classes for a summary

Q 27-2              Which lights or shapes shall a vessel not under command             exhibit ?

A 27-2              Rule 27 (a) and Par. 27.2.1 A vessel not under command shall exhibit:

                        Click on vessel not under command for a summary.

Q 27-3              Why is it important to know whether a vessel not under command is making way through the water or not ?

A 27-3              Par 27.2.1 second paragraph under Notes,

Q 27-4             Is a sailing vessel not under command obliged to exhibit the two red lights prescribed in Rule 27 ?

A 27-4              Par 27.2.1 last paragraph under Notes,

Q 27-5              What exceptions does Rule 27 make towards small vessels (less than 12 metres) not under command.

                        Rule 27 (g) and Par. 27.2.2 Small vessels.

Q 27-6              Which lights or shapes shall a vessel restricted in her ability to manoeu­vre (other than a minesweeper) exhibit ?

A 27-6              Rule 27 (b) and Par 27.3.1  A vessel restricted in her ability to manoeu­vre and underway shall exhibit: (For vessels engaged in minesweeping operations, see paragraph 27.7)

                        Click on restricted in her ability to manoeuvre for a summary.

Q 27-7              Which lights or shapes shall a vessel restricted in her ability to manoeu­vre (other than a minesweeper) exhibit when at anchor ?

A 27-7              Rule 27 (b) (iv) and Par.27.3.2 A vessel restricted in her ability to ma­noeuvre, at anchor, shall exhibit:

                        Click on restricted in her ability to manoeuvre for a summary.

Q 27-8             How should you pass or take avoiding action for a vessel restricted in her ability to manoeuvre (like cable-ships or salvage vessels and the like) ?

A 27-9              Eight and ninth paragraph under Par. 27.3.2.2 By day.

Q 27-10            Which light shall a vessel towing an unable to deviate from her course exhibit ?

A 27-10            Rule 27 (c) and Par. 27.4.1 A power-driven vessel towing and unable to deviate from her course shall exhibit:

                        Click on unable to deviate for a summary.

Q 27-11            Which lights shall a vessel restricted in her ability to manoeuvre, en­gaged in dredging or underwater operations, with an obstruction, exhibit ?

A 27-11            Rule 27 (d) and Par. 27.5.1 A vessel restricted in her ability to manoeu­vre, engaged in dredging or underwater operations, when there is an obstruction, shall exhibit.

                        Click on dredging for a summary.

Q 27-12           Which precautionary measures shall you take when approaching or passing vessels engaged in dredging or underwater operations ?

A 27-12             Par. 27.5.1 A vessel restricted in her ability to manoeuvre, engaged in dredging or underwater operations, when there is an obstruction, shall exhibit, fourth and fifth paragraph (after red or green lights and balls or diamonds).

Q 27-13            Which lights or shapes shall a small vessel engaged in diving opera­tions exhibit ?

A 27-13             Rule 27 (e) and Par 27.6 small vessels engaged in diving operations.

Q 27-14           Which lights and shapes shall a vessel engaged in mine-clearance op­erations exhibit ?

A 27-14             Rule 27 (f) and Par. 27.7.1 A minesweeper shall exhibit.

                        Click on minesweeper for a summary.

Q 27-15            Can one distinguish whether a minesweeper is making way through the water or not ?

A 27-15             Par. 27.7.1 A minesweeper shall exhibit, second paragraph.

Q 27-16            Why is it dangerous to approach a minesweeper closer than 1000 me­tres ?

A 27-16             Par. 27.7.1 A minesweeper shall exhibit, fourth paragraph.

                        Click on presentations for a summary.