"Message in a Bottle" was written by Sting, inspired by the image of a lone castaway throwing bottles into the sea in the hope that someone would find them.
The main guitar riff was Sting's idea that Andy Summers rearranged and transformed into what we know today (and which Rolling Stone named one of the 100 greatest riffs in history). It was The Police's first #1 on the UK Singles Chart (3 weeks at the top in 1979), also #1 in Ireland, #5 in Australia, #2 in Canada... but in the US it reached only #74 on the Billboard Hot 100.