Paul Nash - Down in the Channel
I have been only able to trace the B&W image below of this painting. Its true colours are unknown for now, the catalogue entry states '1940, watercolour, 40 x 57.5 cms, presented to the South African National Gallery by the British Government'.
It shows a Dornier 18 flying boat down on the sea. As the only recorded incidents in 1939/40 involving this aircraft type took place in the North Sea it may be that Nash used artistic licence in placing the event nearer home.