Water Brick: 24H [GRN][BWN][BLK]

This water is potable meaning safe to drink, not portable. In fact at around 1 kg per litre it's a long way from being portable and is a huge logistics challenge on a lengthy trip where people need at least 2 litres a day, or more if travelling or exerting.

The rule of threes says three minutes without air, three days without water, three weeks without food.