It seems to me that the radar screen does not present collision avoiding information in the best form and that we should give some thought to the way in which we would like this information to be presented. Then we should ask the back-room boys to present it to us electronically. It must, of course, be remembered that a ship does not occupy a geometrical point and it will want to escape collision by more than the merest miss. Therefore we should build a margin of safety into the presentation.