Safety update

September 1999 Manoeuvring characteristic of large ships

This safety update is for owners and operators of all vessels. It is issued to raise awareness of the potential serious risk to safety from close quarter incidents between large ships and smaller vessels. It provides safe practice tips for how best to reduce the risk to safety and to alert vessels to their obligations under Maritime Rules Part 22 (Collision Prevention).


There have recently been a number of close quarter incidents between large ships and smaller vessels. Smaller vessels are reminded that large ships have a relatively slow response to rudder movements and cannot stop quickly. Such manoeuvring characteristics must be taken into account by watchkeepers of smaller vessels required to keep out of the way.


A smaller, highly manoeuvrable, give-way vessel may be tempted to delay taking avoiding action. The delay can leave the large, stand-on ship in doubt as to whether or not the smaller vessel intends to take avoiding action. By the time this becomes clear it may be too late for the large ship to take remedial action to best avoid a collision.

Safe practice tips

Vessels are reminded of their obligations under Maritime Rules Part 22 (Collision Prevention), which include:

Every vessel which is directed to keep out of the way of another vessel must, so far as possible, take early and substantial action to keep well clear (rule 22.16)

Any alteration of course or speed or both to avoid collision must, if the circumstances of the case allow, be large enough to be readily apparent to another vessel observing visually or by radar. A succession of small alterations of course or speed or both should be avoided (rule 22.8(2)).

A good knowledge of the maritime rules and an awareness of the limitations of the craft involved can help prevent a serious accident.

Original source content - Boat Notice 101999, September: Manoeuvring characteristic of large ships.

Email updates

Get an email notification when a safety update is available online.


Contact us for more help

If you have any questions about this safety bulletin, please contact our Wellington office.


New Zealand (toll free):
0508 225 522

Call Maritime New Zealand now

Tell us what you need help with and remember to include your contact details (email address and phone numbers).