This is the 4645th most frequent Japanese word.
挺
"挺" means "stick," "arise," or is used as a counter for long, thin objects.
The term "挺" here refers to a type of vessel or ship, indicating a single unit of it.
彼は一本の挺を操縦している。
He is piloting a single ship.
In this context, "挺" refers to multiple ships as part of a fleet.
彼女は全挺の責任を任されている。
She is entrusted with the responsibility of the entire fleet.
Here, "挺" is used to indicate a single unit of an object, in this case, a grappling hook.