Taken from
Wikipedia:
"One of the "hallowed traditions" bestowed upon the area by sojourning sailors, eg. from Australia, was the ritualistic "Dance Of The Flamers" or "Dance Of The Flaming Arseholes" on top of the infamous toilet's roof. Compatriots
on the ground would chant the signature "Haul 'em down you
Zulu Warrior" song whilst the matelots performed their act."