STEP CHANGE FOR SAFETY GLOBAL SHARING DEC 2013 - SAFE NAVIGATION | Page 41

Authorised User (see Terms and Conditions): Member of North of England P&I Association

Rule 6: Safe speed
Every vessel shall at all times proceed at a safe speed so that she can take proper and effective action to avoid collision and be stopped within a distance appropriate to
the prevailing circumstances and conditions.
In determining a safe speed the following factors shall be among those taken into account:
(a) By all vessels:
(i) the state of visibility;
(ii) the traffic density including concentrations of fishing vessels or any
other vessels;
(iii) the manoeuvrability of the vessel with special reference to stopping
distance and turning ability in the prevailing conditions;
(iv) at night the presence of background light such as from shore lights or
from back scatter of her own lights;
(v) the state of wind, sea and current, and the proximity of navigational
hazards;
(vi) the draught in relation to the available depth of water.

(b) Additionally, by vessels with operational radar:
(i) the characteristics, efficiency and limitations of the radar equipment;
(ii) any constraints imposed by the radar range scale in use;
(iii) the effect on radar detection of the sea state, weather and other
sources of interference;
(iv) the possibility that small vessels, ice and other floating objects may not
be detected by radar at an adequate range;
(v) the number, location and movement of vessels detected by radar;
(vi) the more exact assessment of the visibility that may be possible when
radar is used to determine the range of vessels or other objects in the
vicinity.

Check YOUR SPEED

Remember:

Rule 6 requires you to make your own judgement on the appropriate speed
for your vessel, taking into account the situation you are in and the situation
you are moving towards. Excessive speed contributes to many collisions.
Rule 5 on look-out and Rule 6 are closely linked. If you do not obey Rule 5,
then you cannot obey Rule 6.
Without exception a ‘safe speed’ is a reduced speed, because:

• You are responsible for proceeding at a safe speed. If an alteration of speed
is necessary, then you do not have to ask permission.
• Radar and ARPA are not infallible. They may miss some targets altogether
or they may show large targets as weak echoes.
• Navigational aids such as ECDIS and GPS can be equally suspect. Never
rely on one instrument or on one technique – always double-check.
• Constantly monitor your speed – the situation at sea is always changing
and a safe speed in one situation can be too fast in another. Situations can
change suddenly.
• Maintaining a high speed for commercial reasons is no excuse and no
defence for proceeding at an unsafe speed.

• In most cases, if either ship reduces speed, their closest point of approach
(CPA) will increase. The risk of collision will then reduce.
• It gives you more time to think and to act. Time to think and to act is all
important – too much speed and too little time can fatally impair your risk
assessment processes.
• It allows you to stop more effectively.
• If a collision does occur, the resulting damage will be a lot less.

SUMMARY
Always travel at a safe speed.

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