Just curious, but did your submarine use UHT milk? I know here in the Czech Republic, UHT milk is easily the most commonly sold type.
http://en.wikipedia.org/wiki/Ultra-high-temperature_processing
In the Merchant Marine, UHT milk is called “Paul Hall Milk”.
Paul Hall was President of the Seafarer’s International Union. He lasted forever in the position. Hence, a synonym for anything well preserved by artificial means past its prime.
Back in the 80s my wife found small cartons of irradiated milk. It did not have to be refrigerated.
I took them on my Field Training Exercises that usually lasted four days. They were a bit heavy but a nice change from water and powdered coffee.
We ran out of “Real Milk” at about 3-4 days from port. From then on, it was “Plastic Milk” (some kind of dry/reconstituted milk). I am not familiar with the term “UHT Milk”.