text: South African answers U.S. message in a bottle . JOHANNESBURG 1996-08-22 A South African boy is writing back to an American girl whose message in a bottle he found washed up on President Nelson Mandela 's old prison island . But Carlo Hoffmann , an 11-year-old jailer 's son who found the bottle on the beach at Robben Island off Cape Town after winter storms , will send his letter back by ordinary mail on Thursday , the post office said . It will be sent for free . Danielle Murray from Sandusky , Ohio , the same age as her new penfriend , asked for a reply from whoever received the message she flung on its journey months ago on the other side of the Atlantic Ocean .