A 90-TON digger was knocked out of action when it was swamped by the incoming tide.
The £500,000 excavator — being used for coastal defence work — was stranded on a beach by a mechanical failure.
Efforts began to repair the giant scooper before the tide came in.
But when workers realised they could not repair it in time, they switched their efforts to trying to stop fuel leaking into the water.
The cab of the mechanical shovel was then submerged when the sea level rose in Aberaeron, Ceredigion.
It was later recovered but extensive work is needed to get it fixed.
A witness said: “My guess is it will need to be repaired on site.
“It had special transport to get there so it can’t be easily moved.
“The engine will need stripping down and electrics will need replacing because of salt water damage.”
The digger was being used to help build the town’s £32million inner harbour flood defences.
The project, which started in November 2023, involves creating a rock breakwater and flood walls, as well as rebuilding a pier head.
Despite the digger calamity, the scheme is said to be progressing well.
Cllr Elizabeth Evans said: “It’s going great. It’s been horrible weather, we’ve high tides coming but everyone is in great spirits.”
