 Kym Karath (qv) (Gretl) couldnt swim, so the original idea was to  get Julie Andrews (I) (qv) to catch her when the boat tips up and  they all fall in the water. However, during the second take the boat  toppled over so that Andrews fell to one side and Karath fell to the  other. Heather Menzies had to save her instead. Andrews stated later  she felt guilty about this for years.