Pellucid Fly - Volucella pellucens

This fairly horrible looking fly was buzzing around the pond - not one I'd seen before. Once again, Google provided some answers. 

Apparently this is a Pellucid Fly - sometimes called the Pellucid Hoverfly - and is one of the largest flies in Britain, identifiable by its ivory-white band across its middle and the large, dark spots on its wings.