Cotterrell said: “We live alongside the tide, but it’s remarkably easy to stop noticing it.
“I wanted to take that familiar rhythm and place it somewhere it doesn’t belong – inside an object we barely give a second glance.”
He removed the 25-year-old cars’ engines and conventional operating systems and installed tanks, pumps, electrical systems, sensors, filtration, software and bespoke engineering.
Plymouth Culture said as the tides changed, water would move between a hidden reservoir and the visible cabin to create an “unexpected fragment of an intertidal environment within the city”.