Olly I emailed recently re taking water on board Air china=--i found this on an air china website if it is accurate "In accordance with regulations of the CAAC, a passenger should not travel with more than two bottles (each bottle should not be over 500ml) of carbonated drinks, mineral water, tea, milk, acidophilus milk, juice, etc. Passengers can purchase drinks after the security checks in airport/as long they are in compliance with the limits." Iff this is the case i should be able to manage as ythis couple with what they supply will be fine--sorry for the panic