According to Official Guinness Records,
The farthest distance covered on a water slide in 24 hours by a team is 843.33 mi (1357.22 km), achieved by Daniel Gildner, Falco Tegtmeier, Kai Falk, Manuel Wasserzier, Marius Toborek, Rudolf Hofmann, Marc Fugger, Andrej Sonnenberg, Stefan Kleinöder, Thomas Renner, (all Germany) at Galaxy Erding in Erding, Germany on 11 and 12 November 2009 in celebration of Guinness World Records Day.
For a complete list of 2009 records, please visit 2009 Guinness Records in Germany.