Flights from Buenos Aires Water Situation in Coach

Delta, please be kind and help here. Flights from Buenos Aires take away your water bottle you purchased after security but at boarding. Therefore, for this nine-hour flight, you do not have a water bottle if in coach. Please Delta, hand out small water bottles to everyone like the old days. Some of us get so dry on the plane during these long flights and also must take medication at certain hours. The cups are not good because you have to drink all at once instead of taking sips throughout the flight. I can get my own water bottle for coach, except this was a surprise at the gate. If I had known, I would have had an empty bottle to fill on board, but everyone cannot be doing this.