Features Editors: Paris: Kate Millar +33 1 4041 4636 Hong Kong: Liz Thomas +852 2829 6211 Twitter: @AFPfeature We are offering the following item: + In Colombia, fleet of cartel narco-subs poses challenge for navy Colombia-drugs-military,FOCUS TUMACO, Colombia For years, they were referred to in hushed tones simply as "Bigfoot" -- a mythical creature rumored but never seen -- but these days, the narco-submarines used by Colombia's drug cartels have become almost commonplace. And the navy is fighting back. 900 words by Florence Panoussian. Pictures by Luis Robayo. Video by Juan Restrepo afp