 The original 1962 print had a different opening scene, in which a ships crew  lands on Pitcairn and discovers an artifact belonging to the H.M.S. Bounty.  They can barely read the name until William Brown (Richard Haydn), now aged,  appears on the beach and says "Bounty". He then proceeds to tell the story of  the famous mutiny, of which he is apparently the last surviving member. That  is why we hear his voice narrating the story. In all current prints,  including the one shown on Turner Classic Movies ca. 2005, this opening scene  is omitted, so we do not know why Brown is telling the story in voiceover.  However, the scene has been restored on the 2006 DVD release.