Migrant crisis: Aboard the Aquarius as it returns to sea

The search-and-rescue ship Aquarius spent last week in the middle of an international diplomatic row, after it was turned away by Italy and needed to find a port for the hundreds of stranded migrants it had rescued.

Spain eventually allowed the ship to dock - and now it's back at sea in the Mediterranean, searching for more people in need of rescue.

BBC's Gavin Lee is with them.