My late grandfather served onboard the USS Sablefish (SS-303) during the Korean War. He told me that they used to have an ice cream machine onboard that they were able to help themselves to whenever. They also used to mess with the other sailors by putting stuff inside the machine like socks (why? no idea.) I was just wondering how popular self-serve ice cream machines were amongst US and other world's naval fleets.
Ice Cream aboard U.S. Naval vessels was and still remains extremely popular as the chow served in the mess can get extremely dull and repetitive after weeks at sea. It first started being served aboard U.S. Naval Vessels in 1893. One of the reasons given for it's introduction was that it was an easy way to get sailors their calcium nutrients without having to worry about thawing out large quantities of frozen milk or keeping refrigerated milk that would go bad after a few weeks at sea. Ice Cream, along with other snack foods, is typically served out of the "Gedunk" which was usually just a ship store aboard the ship that sold or distributed these items to the crew.
Couple of funny stories about ice cream's popularity with the Navy. Usually, the ice cream machines during WWII and Korea were only found on larger capital ships and submarines since smaller ships didn't have the precious space or the resources to keep them. So often, whenever a smaller vessel, such as a destroyer or transport ship, rescued downed Navy and Marine flyers, they'd "ransom" them back to the carriers for a batch of ice cream for their crew.
Another Story I recall hearing that supposedly took place is that one afternoon as one of the enlisted watches was waiting in line for their ice cream, two ensigns decided they would pull rank and skip to the head of the line. The enlisted men grumbled about this, but made way, and as the ensigns made their way forward, a higher-ranking officer in the same line ordered them in a rather curt manner to get to the back of the line or he would have them both stand before the mast. Both ensigns returned to the back of the line without complaint. The higher ranking officer was non-other than Admiral Halsey.
Sources:
Halsey's typhoon : the true story of a fighting admiral, an epic storm, and an untold rescue