In June 1820 Lloyd's List reported that Cossack, Walker, master, had struck on Alcide Rock, near Bic Island.

She was on a voyage from Liverpool to Montreal but had to discharge her cargo at Quebec as she had sustained damage.

There was a report that on 15 January 1821 Cossack, Walker, master, had arrived at Madeira and had sailed the next day for Bombay.

A report from Milford, dated 4 December 1823, stated that Cossack, Walker, master, with a cargo of lumber, had run ashore at Newgate Sands.

She was a complete wreck but it was hoped that her materials and cargo could be saved if the weather was moderate.