Indeed Canberra, as I illuded in my original post, BE are very much aiming the NWI flights at cruise pax. I am booked on a P&O cruise myself in April, and although not relevant for me as I am approx. 40 miles from SOU, there were a lot of offers available on flights into SOU from regional airports with BE.
Incidentally, this flight could easily be identified from the outset as a franchised operation (ie, Loganair or Suckling) - the flight number format (BE6xxx) is the giveaway.