It’s a Sunday. You’re a Mayor, and you’re a local councillor, with a host of local duties, as well as your work and your family to think about. And here’s a chance for a bit of time off. And, frankly, sailing isn’t really your thing. But you can spot a good cause when you see one, so you lose a fat chunk of your day off to open the latest facility, a new pontoon, at the Welsh Harp reservoir in the North London Borough of Brent. So full marks (and a bit more) to the Mayor of Brent, Councillor Kana Naheerathan and Councillor Sury Khatri from neighbouring Barnet. Here’s the thing though – bizarrely, part of the lake is in Brent and part in Barnet. So… how do you draw a council boundary in a lake? These are deep waters, Watson…