There are occasions when, because of the density of shipping and/or lack of sea room, ships navigating by radar in thick weather cannot avoid passing within a distance of two miles, the least distance usually considered desirable. In such a situation a simple plan of procedure and of avoiding action, if possible to devise, should greatly reduce strain on the navigator and so increase the safety of navigation generally. Also, if such a plan came to be generally followed, safety would be further enhanced, because each navigator would know what the others were likely to do.