Talk:The 21-Second Excitation/@comment-190.232.0.234-20141114012155/@comment-1410838-20161224012323

To be a little more specific, submarines of the time used electric engines to operate submerged. These engines, in turn, ran off batteries that were charged by the crafts' primary engines, which were diesel and required air for combustion. It's for this reason that they operated at the surface most the time and only submerged when attacking or shadowing surface shipping.

Wolowitz, being an engineer, should know this.