swivel sub

例句：

1. 1. The submarine was maneuvering through the dark waters.
   潜艇在黑暗的水域中机动。
2. 2. The submarine captain had to make quick decisions underwater.
   潜艇船长必须在水下迅速做出决定。
3. 3. The submarine's swivel sub was a crucial part of its navigation system.
   潜艇的操纵轮是其导航系统的关键部分。