Answer:
An adverb is a word that modifies (describes) a verb (he sings loudly), an adjective (very tall), another adverb (ended too quickly), or even a whole sentence (Fortunately, I had brought an umbrella). Adverbs often end in -ly, but some (such as fast) look exactly the same as their adjective counterparts.
Pequod's preparation was overseen by men who owned the ship together with Ahab but were no longer sailors, they were now just investors and owners. They didn't know what Ahab was planning and what would happen to the crew and they probably would've stopped it if they had known.