Going for a walk along the Thames this evening, I watched a boat go past. Not your usual boat - this was one of the inshore lifeboats with crew of 4, at full speed with its blue lights on and sirens blazing. Now, I've seen boats (*) nailing it along this stretch before, but they usually either slow down by the moored boats further up, or turn round and go back slowly, which suggests that they're just practising on the clear stretch (or having fun). However, this lifeboat didn't slow - it kept on going full speed, full sirens under Hammersmith bridge and on round the bend out of sight. I assume that it was off to someone for real. I hope that it all ends well.
* - police boats and a fire boat on this stretch, and customs boats and Port of London authority boats lower down between Tower Bridge and London Bridge. I think that that completes the list of organisations with boats which have lights and sometimes break the speed limit on the Thames.