Sorry chaps, I have mislead you all, and I thank you for your patience in trying to help me.
I think, having gone through every page in the handbook the warning symbol is not the "Water in fuel oil filter" but the Selespeed "failure warning ".
The thing lights up for a few seconds every time I turn the ignition on and looks as though it represents a pictogram of a clutch pedal.
Why I got the warning and bleeping the other evening is a worry. Fortunately the car goes for service in a couple of weeks to my trusted indie Mike at Roberts Aerospace, who I am sure will sort it out.