Crikey..... it was! And given that it was approx 150-200m away over the trees, a bloody big one! Even my camera lens could lock focus on it! It was basically hunting flying insects much like the hirundines but at 3pm in the afternoon!!!!
Given the size, it has to be a Noctule (any comments on this welcome!) which has a wingspan of over 30cm which would fit with what we were watching....
And I later cursed myself for not being quicker off the mark to investigate closer!!
By the time I reached the fen hide over which it had been flying..... it was no longer airborne or simply gone!
And the LRP made an even smaller object in the frame on the far island!!!
I'm sure there will be a closer one soon!!