‘How can nudity be so provocative?’ Florentina Holzinger on rocking Venice with naked jetskiers, human bells and urine divers

The artist’s Austrian Pavilion, which features a performer ringing a bell with her body and another immersed in the audience’s own urine, is the talk of the biennale. Why is she so surprised by people’s reaction?It’s a damp Venice morning. In the middle of the lagoon, art world luminaries with dripping umbrellas are climbing on to a boat with raked seating to witness a one-off performance. Stationed opposite them is a barge fitted with a large crane, its boom extended high above the water, its heavy anchor chain plunging into the turbid depths.Women, naked but for tattoos and boots, emerge on to the deck of the barge. Directed by a bandleader in rubber waders, some pick up instruments and create an intense wall of sound. The electric guitarist clips herself on to the slippery crane, climbs to a vertiginous height and rocks out while straddling a steel bar. She is joined by a vocalist who screams and squalls like Yoko Ono. After 20 minutes of heavy drone, the boom rises, hoistin