Captain R. K. Emden in his paper in the April 1975 issue of this Journal notes on page 135 that ‘the chief problem’ is ‘to identify by name and port of registry the radar “blip” deemed to be a contravening ship’, and that ‘the problem will be exacerbated as the Service expands’. In the discussion which followed Commander R. B. Richardson mentioned the m.f./d.f. receivers being used to assist ships to keep in lanes, and Captain Lusted mentioned investigations into the use of shore based v.h.f./d.f. for identifying ships.