Ask a SEAL what that’s like, and they’ll say it’s like being locked in a cold, dark, wet closet for hours.

“Ever take an ice bath?” said a SEAL who spoke to The Hill on the condition of anonymity. “It’s a tall order.”

After they reach their target and conduct their mission, SEALs have to make it back home, often the same way they came.

The new vehicles, which are called dry combat submersibles, will be akin to mini-submarines, and allow SEALs to stay warmer and drier for longer, and more physically ready, as they close in on their target.