By the tenth century C.E., North African Arabs had invented a device for gathering coral ​ — a large diagonal cross, the beams of which measured between 13 and 16 feet [4 and 5 m] in length.
Kümnendaks sajandiks olid Põhja - Aafrikas elavad araablased leiutanud seadeldise, millega koralle koguda – suure diagonaalse risti, millel olid 4 – 5 meetri pikkused talad.