As the funeral procession made its way over Lambeth Bridge, boats from the Marine Policing Unit led river emergency services and lifeboats in a ten-second horn salute.
The boats formed an arrow shape as NPAS helicopters flying above created the ‘missing man formation’ salute – commonly done at funerals and memorials.
One of the police helicopters broke away and hovered over the Cathedral and, as PC Palmer’s coffin was carried in, performed the ‘bow’ manoeuvre.
Hundreds of officers from police forces all over the country arrived on coaches in Southwark hours before the funeral which is thought to be the largest ever gathering of officers in Britain.