Thanks Pace, there were 2 of us onboard (both pilots) with one flying/keeping an eye on our home airfield whilst the other took photos. At all times we had 2 extra airfields visible (Stapleford nearby, and Southend in the distance) - we told ourselves that if either of these fogged over then we'd immediately land. As it stood, the fog stood rooted in pretty much the same spot for the entire 2 hours that we were airborne!
A few more below for anyone interested.
