Cluster ballooning

This photo, released by the Brazilian website UOL, shows Catholic priest Adelir Antonio de Carli, 42, suspended under a cluster of brightly colored party balloons in Paranagua, Brazil, April 20, 2008. Rescuers reached the balloons floating in the ocean off Brazil's coast Tuesday, but did not find the priest who had been using them in a bid to set a flight record and raise funds for his parish.

It is left as an exercise to estimate the number of helium balloons required to suspend an average priest. Take r(air) as 1.2 kg/m3.