During the war there were no lights, no street lamps, not even house lights, it was a complete black-out. However, even in the darkest of nights, the difference between land and water was clearly visible from the air. And the Netherlands, with the Frisian Islands, the Afsluitdijk (the dam across the old Zuydersea), and the rivers, were an extremely excellent and easy back-up for the navigation of the Allies. Too as the navigation at the time was completely different to the navigation of today. and in addition Flevoland, then known as IJsselmeer and Zuydersea, was in principle Flak free. The Germans had Flak defences all over the Netherlands, but strangely on the coast at Egmond, no heavy Flak. The heavy Flak defences overlapped each other but during the entire war there was always 'that hole at Egmond. I don’t know why this was.
If allied airmen were in trouble, shot at or whatever, they always took the shortest route over the IJsselmeer (less Flak) and once at Egmond, they had a reasonable chance of getting home. Flevoland played an important role in the war because of the near pinpoints! Stavoren, Urk, Noordoostpolder. Easy to navigate from the air.
The land was, for most part, still under water. However, aircraft had landed in the polders area's and after the war we salvaged several planes.
The flight path often ran across the IJsselmeer. Not specifically over Urk but Urk was a well known navigational pinpoint for the airmen. On the other hand, it was only natural for the fishermen of Urk to get involved at sea if a plane had been shot down. Picking people out of the sea and saving lives. The Allies knew that the Ijsselmeer was used for fishing. The also kept an eye on the North Sea Fishery, for the Allies knew, for example, that German soldiers could be on board. Reporting the flight routes of Allied airplanes. They were well aware of this in England.