Just browsing my favourite aircraft tracking website and decided you should know that air-to-air refuelling gets practised off the Norfolk coast. See this Voyager aircraft enjoying the baking weather in this country.
The green box is the area they are allowed to practise. The red planes are military planes, not all of them, but those transmitting ADS-B. I would expect that some Typhoons are over the sea taking on fuel from the Voyager.