In 1952 the Institute set up a working party, with Captain F. J. Wylie as its chairman, to make a study of the desirability of plotting radar observations of other ships, to investigate the relative merits of different ways of plotting, taking some account of the errors involved in each, and possibly to make general recommendations on the use of radar for avoiding collisions at sea. The working party has completed its study of the desirability of plotting and of different systems and methods and the report on this part of its work is given here. It is now engaged in assessing the magnitude of errors of observation and computation and the results of this assessment will be published in due course.