The Guinness Book of World Records recognizes the highest altitude attained via cluster ballooning to be that achieved by Mike Howard (UK) and Steve Davis (USA), who on August 4, 2001, over Los Lunas, NM, USA, used 400 helium balloons to reach a height of over 18300ft.
Yoshikazu Suzuki departed from Lake Biwa in Japan on 23 November 1992 with 23 helium balloons.