Thanks everyone!
Xan - the concept isn't based off a photograph, but I got the idea many moons ago when I saw Stan Stokes' painting "Gotcha":

I've chosen a different aircraft (I am thinking an Albatros painted in markings from mid / late 1918, when they were very much outclassed), a different angle into the water (slightly more dramatic), and a different pilot (to help tell the story), but the basic concept is there in the painting.
There's still every chance at this point that i'll stuff this one up - I've not tried terrain like this before so I am doing a bit of reading to work out how to do it best... i've just spent a small fortune this weekend at my local hobby store buying model railroad supplies as well as various other things, so before I take the concept much further i'll see how well the terrain work goes.
Cheers!
BC