Experience gained in equipping some 24 vessels, varying in size from 700 to 4000 tons, with radar may be of interest, and perhaps of help in avoiding some of the pitfalls that can occur.

The problem of finding sufficient space in a small ship so that one instrument does not interfere with another is never an easy one. For example, to fit radar to a vessel whose wheelhouse superstructure is not more than 10 ft. long may entail building a radar tower of considerable height if the proper distance between the scanner and the magnetic compass is to be maintained. The magnetic effect of the tower on the compass will then have to be considered, and it may be necessary to build it of a non-magnetic material. Also the effect of the radar, when working, on the D.F. loop arises; a distance of 12 ft. between them is here necessary.