The National Geographic magazine has run a '
Goblet of Fire' feature with some new tidbits of information from the cast members. The four scans can be viewed
here.
Quote:
Although the actors learned how to scuba dive for the underwater scenes, Katie Leung, who plays Cho Chang, was so light she had to wear weights on her legs to keep from floating to the surface. It worked - sometimes. "I'd still float up," she says. "The professional divers on the set would have to pull me back down."
Source:
RupertGrint.net