Originally Posted by
peterh337
Why Southampton?
in the context C421 provides, I would guess the argument for Southampton could be
EGKA has only NPA and being right on the coast could be subject to fog, locally low ceilings. Southamption, being slightly inland and with an ILS will likely still be available if the weather at Shoreham goes below minimums. As a bonus, Southampton is a 'better' place to get a car/train home from than any other sensible alternate.
This is particularly true if the TAFS and general weather picture don't show both airports in the same system of persistent low cloud and fog!