Are sealed 1.5 litre bottles of water allowed through security? I don't really want to have to fork out $7 for a bottle of water at Perth International Airport once we've gone through security, since I just bought some 1.5 litre bottles at the supermarket for 75 cents each. I'm pretty sure last time we went anywhere from Perth International (August 2008) there was nowhere to fill a water bottle, except from the handbasin in the toilets. We need to have a decent amount of water as my husband suffers seriously from ear pain and he usually drinks at least one litre of water during descent. Those small glasses of water on the plane just don't help.