naval base
A military base for naval operations, including ports, docks, and support facilities.
横須賀には大きな海軍基地がある。
There is a large naval base in Yokosuka.
空軍基地 is an air force base, while 海軍基地 is specifically a naval base.
陸軍基地 is an army base, contrasting with the naval focus of 海軍基地.
Compound of 海軍 (navy) and 基地 (base).