The underwater scenes were planned to be shot underwater in an Oxfordshire lake, in the UK. On the day of shooting, attempts were made to enter the lake but it was discovered the amount of silt at the bottom was so deep, the shoot would become dangerous. Th underwater scenes were eventually shot in the sea at a Southern England seaside town, and even then... the fates were against the cast as it was a cold sea, pouring with rain and very cold. The only people in the sea that day were the crew and cast and onlookers thought them mad.