[The Conversation Africa] Gales tore at the Mary's sails, and surf crashed across the brig's deck. Seventeen-year-old Nathaniel Isaacs tied himself to a railing to avoid being washed overboard. The Mary's rudder soon splintered against a rocky bar at the entrance to Natal Bay - what is now Durban, South Africa. Helpless to maneuver, the ship took on water.