The emergency services rescued a driver after his bus became stuck in the mud off Osea Island causeway.
The South Woodham Ferrers coastguard was called out just before 6.30pm last night to reports that the red and white double decker had come of the causeway.
Essex County Fire and Rescue Service and Essex Police were also called to the scene.
A coastguard report said: "On arrival we liaised with fire and police officers who were at the start of The Causeway.
"Coastguard Rescue Officers along with a fire officer, made their way to the driver of the bus who was still with the vehicle, located approximately halfway across The Causeway.
"The driver was safely recovered to main land, whilst CRO's awaited the arrival of a recovery vehicle.
"CRO's remained on scene to provide scene safety until the vehicle was safely recovered and all vehicles clear of The Causeway for the rising tide."
The coastguard crew returned to the station at 10pm.