A coastguard officer had to be pulled to safety after being shoved into the River Medway while on duty.
Medway Coastguard said a member of their team was pushed off Gillingham Marina while they were investigating a distress flare at 0050 BST on Sunday.
He managed to radio his colleagues who pulled him out of the river.
Colin Ingram said: "Behaviour like this to a member of the Emergency Services whilst out endeavouring to save someone's life is appalling."
He added: "Fortunately the officer is safe and well with slight grazing."
Kent Police are investigating the incident.