It almost created the illusion of invisibility – no mean feat for a 68m-long superyacht owned – as it sidled out of its home for the last four days under a very dark sky.

Two fishermen were gazing so intently into the water as the Archimedes sailed by the SS Great Britain that they only noticed the £75m vessel as it was almost upon them.

Drivers heading to work along Hotwell Road got out of their cars to take a closer look at the billionaire’s plaything, while Harbour Master staff opened bridges and lock gates to allow the boat to pass.

It was a tight squeeze as it passed by the Pump House, and it then had a wait of about 15 minutes from 5am for Plimsoll Bridge to swing open, before waiting for another 15 minutes in the lock for the water levels to rise.

When the lock on the River Avon side opened, a member of the Harbour Master’s team untied a rope, gave a cheery wave and the Archimedes continued on her way.

A ship that had captured the imagination of Bristol was soon dwarfed by the Suspension Bridge, created by one of the city’s most famous sons, as it navigated the bends of the Avon towards the open sea.