The overnight rescue effort took more than two hours because extremely thick fog complicated efforts to find the boat, the CROSS maritime authority said in a statement today.
It said the migrants were found not far from the Calais coast, suffering from mild hypothermia, and handed over to border police.
Migrants fleeing war and poverty in the Middle East and Africa continue to converge on Calais in hopes of sneaking across to Britain, despite the closure of a vast migrant camp there last year.