Only the start is subject to the river closures.
It will also affect all boats using pontoons on the Surrey bank as they are all closed. The PLA will have a cross over point so the boats can change over to the Middlesex bank down near Canary Wharf. I think the general notice is stay close to the Middlesex bank anyway. I dread to imagine what will happen if you head towards the south bank, some of those marshall boats are driven by nutters!
Speaking of which, say hello to us at Westminster Bridge, Blackfriars and HMS Belfast!!!!
PS keep your eyes open for the beer barrel which races every year!