Bristol grew rich as a Georgian-era trading port on the tidal River Avon, but the Avon's huge tidal range — over 12 metres at spring tides, one of the largest in the world — left ships stranded and keeled over in mud at low water. The solution, completed in 1809, was the Floating Harbour: a dammed, lock-gated basin that keeps the water level constant regardless of the tide outside, so ships stay permanently afloat.
Today those same quaysides and warehouse walls carry Bristol's globally-known street art scene (Banksy grew up here), painted directly onto the Georgian and Victorian brick that once stored sugar, tobacco and other trade-ship cargo.
The Matthew, John Cabot's ship that reached Newfoundland from Bristol in 1497, and Brunel's iron-hulled SS Great Britain (1843) are both real ships still moored in Bristol's harbour today as museum vessels — represented here in simplified form.
A 3D model of Bristol's tidal River Avon and its Floating Harbour, showing how lock gates built in 1809 keep ships permanently afloat despite one of the world's largest tidal ranges — with a toggle that layers street art onto the historic warehouse quaysides.
Outside the lock, water follows the tide freely; inside, closed gates hold a constant level so ships never ground in mud — the actual engineering problem the Floating Harbour solved for Bristol's Georgian trade.
Slide the tide level and toggle the lock gates to see the harbour drain or stay full. Drag the era slider from the 1780s to today, and switch on the street art overlay to see murals appear on the quayside warehouses.
The Matthew and Brunel's SS Great Britain — both represented here — are real ships still moored in Bristol's harbour today as working museum vessels.