'Ciudad de Cadiz' blown off the berth to ground near Mostyn Harbour on the Salisbury Bank, River Dee in North Wales.
The vessel had been berthed alongside in Mostyn Harbour when the mooring lines parted in 60 knot winds. She then drifted onto a sandbank.
Hugh Shaw, Secretary of State's Representative for Maritime Salvage and Intervention, said:
"Attempts have been made to re-float the vessel using two tugs, and this afternoon the bow of the vessel has moved but the stern is still stuck."
Another attempt to free the ship will be made at the next high tide.
"We are closely monitoring the situation, but as there is no evidence of damage to the hull, the risk of pollution is very low," added Mr. Shaw.