Watchkeeping and the COLREGS

3.2.3.1 Lights, shapes and sound signals

The OOW must always comply with the COLREGS. Compliance not only concerns the conduct of vessels under the steering and sailing rules, but displaying the correct lights and shapes and making the correct sound and light signals.

A vessel drifting off a port with her engines deliberately shut down is not, for example, a 'vessel not under command' as defined by rule 3(f) of the COLREGS.

Caution should always be observed when approaching other vessels. Vessels may not be displaying their correct light or shape signals, or indeed their signals

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Guicance то masters anc navigating officers

could be badly positioned and obscured by the ship's structure when approached from certain directions. In sea areas where traffic flow is regulated, such as port approaches and traffic separation schemes, it may be possible to anticipate movements from certain ship types. In these circumstances it is prudent to allow extra searoom, as long as it is safe to do so.

3.2.3.2 Collision avoidance action

In general, early and positive action should always be taken when avoiding collisions, and once action has been taken, the OOW should always check to make sure that the action taken is having the desired effect.

VHP radio should not be used for collision avoidance purposes. Valuable time can be wasted attempting to make contact, since positive identification may be difficult, and once contact has been made misunderstandings may arise.

3.2.3.3 Collision avoidance detection

In clear weather, the risk of collision can be detected early by taking frequent compass bearings of an approaching vessel to ascertain whether or not the bearing is steady and the vessel is on a collision course. Care however must be taken when approaching very large ships, ships under tow or ships at close range. An appreciable bearing change may be evident under these circumstances but in fact a risk of collision may still remain.

In restricted visibility, conduct of vessels is specifically covered by the COLREGS. In these conditions, radar and in particular electronic radar plotting can be effectively used for assessing risk of colision. The OOW should take the opportunity to carry out radar practice in clear visibility, whenever it is possible.

For details concerning the use of radar for collision avoidance, refer to section 4.2.2 of this Guide.

Date: 2016-04-22; view: 1149