Bonjour
I confirm that 3l a day is a good value but I would take an extra 50% spear plus 20 litres as a rescue reserve.

As I don't have any water tanks, the water is in bottles.
Caution : for the return the 1 gallon US bottles are not waterproff so I transferred the US water into European empty bottles.

200 l, in weight, is less than two crew members and empty bottles provide extra flotability reserves!

Eric