Since the introduction of the present (1960) Regulations for Preventing Collisions at Sea, we at Cardiff have noticed that the actions taken by Masters and senior officers, during simulator exercises, have been bolder and, perhaps, taken somewhat earlier than they were previously. Unfortunately, however, the actions taken by two ships approaching each other often cancel out. This is not always dangerous because the initial actions have generally been taken early enough for further action to be taken but, it does lead to unnecessary delays and frustration. We think, therefore, that it is desirable that any new Regulations should contain a set of rules of action for a vessel detecting another, on a collision course, by radar only.