mudlarking

waiting for the train back
we stood on Blackfriars bridge
watching the rippling green water
slide silently along beneath us
how often is the tide
high and low she said
twice a day, I said
six hours to high tide
then six hours to low
it’s got something to do
with the sun and moon
but I’m not sure how
we watched a tourist boat
foam noisily towards the bridge
a voice on its tannoy
pointing out things of interest
which at that particular moment
included the bridge, and us
tide is turning, I said
as the sun was sinking
behind the new city scrapers
whilst down on the shore
a man on the mudflat
dug for coins and whatnot
something of people long gone