We're talking aeroplane water from aeroplane tanks here, heated in a boiler to make instant coffee here! It's a gross way of drinking anything, but unfortunately, the need for frequent tea overrides the horror of where it comes from. Imagine the water tank, under the floor, also feeding the toilet system. Look 'into' it with your x-ray eyes- what do you see? Water sloshing backwards and forwards, sea weed stuck to the sides of the tank waving about with it, the odd empty cigarette packet and rusty spanner lying on the bottom! I hope he enjoyed his coffee!