The congregations of Southwark Cathedral and the parish church of St Magnus the Martyr in Lower Thames Street gather in the middle of London Bridge for the annual ceremony of the blessing of the river.
Since the building of the first bridge across the Thames, the spiritual care of all those who have used it has fallen to the parish churches located at either end.
In a ceremony that draws on traditions throughout Europe, prayers are offered for all those who use the river for work or leisure.
This Thames tradition follows the Orthodox custom of hurling a cross into water as a symbol of Christ's birth and baptism which is celebrated on the Sunday after the Epiphany.
All are invited to join the congregations for this occasion.