The unmanned 19ft (67m) barge, the Goliath, was being towed by a tug when it started taking in water as it approached the Port of Dover just before 5am.
The planned entrance to Dover Harbour was abandoned and the tug, the Sea Alpha, manoeuvred the barge towards the beach near Walmer and secured it with lines.
Andy Roberts, sector manager for east Kent at the MCA, said this was just a precaution and the agency did not expect any problems with pollution.
The view from Walmer Castle was impressive, as the cannon was trained on the vessel as if in readiness for an invasion.
The Anglian Monarch, a Coastguard Emergency Towing Vessel stood by in case she was needed. She has enough horse power to pull a super tanker through a storm so the barge-crane, Goliath would be no problem.