Stena Mersey was launched in December 2005 as Mersey Viking, entering service with Norse Merchant Ferries later the same month.
A few months later, Norse Merchant Ferries was acquired by Norfolkline.
Mersey Viking received Norfolkline lettering on her red hull but retained her Norse Merchant Ferries funnel for several years.

In July 2010 Norfolkline was acquired by DFDS.
The vessel was renamed Mersey Seaways during her refit in August 2010.
Later that same year, DFDS sold its Northern Irish operations to Stena Line.
 In August 2011, the vessel was renamed Stena Mersey
Early in 2012, Stena Mersey, along with her sister ship Stena Lagan, was given a complete interior and exterior refit and repaint at Harland and Wolff.
Stena Mersey was launched in December 2005 as Mersey Viking, entering service with Norse Merchant Ferries later the same month. A few months later, Norse Merchant Ferries was acquired by Norfolkline. Mersey Viking received Norfolkline lettering on her red hull but retained her Norse Merchant Ferries funnel for several years.
In July 2010 Norfolkline was acquired by DFDS. The vessel was renamed Mersey Seaways during her refit in August 2010. Later that same year, DFDS sold its Northern Irish operations to Stena Line.  In August 2011, the vessel was renamed Stena Mersey
Early in 2012, Stena Mersey, along with her sister ship Stena Lagan, was given a complete interior and exterior refit and repaint at Harland and Wolff.
MS Stena Mersey