The 'Jesus stunt' was a publicity drive for Dynamo's new TV series Magician Impossible – and it is believed the river police were part of the set-up.
But what was 100 percent real was the amazement on the faces of the tourists on the Thames bank as they watched the mind-boggling trick.
Dynamo, whose real name is Steve Frayne, is a 28-year-old illusionist from Bradford.
His previous tricks have included making Little Britain star Matt Lucas levitate before a live audience at Arsenal's Emirates Stadium, and turning signed lottery tickets into cash in front of Robbie Williams and Davina McCall as part of BBC's Sport Relief live programme.
Dynamo cleverly targets celebrities and previous marks have included:
and Natalie Imbruglia.