Guide dog Vance knows where he's going

I'm sure that many of the people I come across whilst travelling around London think that I simply tell Vance the address of the place I want to visit and off he goes, as if he possesses the latest in canine satellite navigation. Well, on this occasion Vance excels himself, showing off not only his biological compass but also his powers of telepathy, changing trains at Waterloo with barely an instruction from me.