Rejoice, Girls Und Panzer fans! We got an awesome OVA, Water War, heading our way. It's a special short (about 10 minutes) where the girls have a day out on the beach. It's included as a part of the limited Blu Ray release which has the whole first season, a box desgined by Humikane Shimada, a 32 page design book and nine playing cards that is illustrated by Isao Sugimoto.
It's priced at 7,000 Yen ($83.88 USD See CDJapan.co.jp) and released on December 21, 2012.