NavList:

Francis said:

> ... RDF, although hardly “traditional navigation method” is quite good fun.

It's perhaps closer to "traditional" in that, unlike most modern electronic navigation, it doesn't just spit out a fix. RDF yields an LOP with a significant degree of uncertainty which must be combined intelligently with other data to develop a position.

Case in point: the 1981 Marblehead to Halifax race. As usual it was foggy pretty much the whole way, so the sextant never came out of its box. I relied on LORAN for fixes until the second night, when one of the two slave stations went off-line. The LORAN would no longer produce fixes, but would give the TD from the remaining slave, which gave a precise LOP. The sequenced RDF beacons along the Nova Scotia coast could then be added to give acceptable fixes, occasionally confirmed via the depthsounder when we passed a sharp bottom contour. This was most reassuring, since the strong tidal currents make DR alone kinda iffy. So, while all my inputs were electronic, it required judgement to assemble and evaluate the fixes that they produced. I was proud (but not surprised) when the buoy off Sambro Island appeared right on our bow after seeing nothing but fog for three days.