Astral is one of the last NGO-run rescue boats in the Mediterranean.
It says it’s saved 25,000 lives in this area.
Italy, by closing its ports and accusing NGOs of being ‘migrant taxis’, has made its work harder.
Italy says its measures have cut migrant traffic by 80%.
A BBC team travelled with the Astral for eight days.
On board the ‘last’ migrant rescue boat