II—Some Navigation Radar Problems

Extract

Captain Jones has indicated that the navigator needs improved technical assistance in avoiding collisions during conditions of inadequate visibility. When the aided eye fails to distinguish the aspect of a vessel until it is much closer than the optimum distance at which a risk of collision ought to be recognized, then visibility is inadequate. For large ships a warning can be required before the distance closes to three miles, for example, whereas a visibility limited to three miles is commonly experienced. However, more guidance on this point is still needed from navigators.