Remember this chap ( my hero! ):
http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=56613
Slowest Olympic Heat Winner
He had only learnt to swim nine months earlier, had never raced over 100 meters, and had never even set eyes on a full-size swimming pool! But Eric Moussambani took to Olympic swimming like a fish to, um, dry land! Having trained in the rivers of Equatorial Guinea, the sight of Sydney's International Aquatic Center must have been a daunting sight. Maybe Eric's big race nerves were calmed by the absence of any competitors, his two fellow qualifiers having been dismissed for false starts. Either way, he emerged a hero one minute 52.72 seconds later (around half as fast as the top swimmers), as the slowest Olympic heat winner ever!
http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=56613