Once a support and rescue vessel for offshore oil platforms, the Ocean Viking has undergone several changes to fit its new purpose: rescue migrants from drowning as they attempt to reach Europe by sea.
Built in 1986, the Norway-flagged ship is 69.3m long and 155m wide and can reach a speed of 14 knots. It is also able to manoeuvre fast despite its size.
The Ocean Viking was recently chartered by SOS Mediterranee after the group lost its previous rescue ship, the Aquarius, after a series of standoffs with Italian and Maltese authorities.
What was once a spacious deck now houses a medical clinic, with four hospital beds, a large shelter for men and a separate and smaller shelter for women and children.
Decorating the metallic shelters are animal figures, a map of Africa and Europe, a clock and drawings made by the previous rescuees.
One of the closed containers, empty for now, reminds migrants of the risks facing their perilous journey: death.
At least 640 people have died so far this year according to the International Organisation for Migration (IOM), and nearly 16,000 migrants have died on that route since 2014.
SOS Mediterranee started operating in February 2016 and has since rescued 30,000 people — mostly with its former ship, the Aquarius, but it has also witnessed 47 deaths at sea.