An installation comprising a graduated glass tube, connected at the bottom end with the sea and with the top end open to the air, on which the draft of the vessel is shown by the level of water in the tube.
Ufakelo oludibanisa iityhubhu zeglasi, oludityaniswa kwisiphelo somphantsi ngolwandle nangesiphelo somphezulu esivuleke emoyeni, ekulapho idrafti yenqanawe iboniswa linqanaba lamanzi akwityhubhu.