Sentence:  With finger pointed and eye levelled at the Pequod, the beggar-like stranger stood a moment, as if in a troubled reverie; then starting a little, turned and said:—“Ye've <WSD>shipped</WSD>, have ye? Names down on the papers? Well, well, what's signed, is signed; and what's to be, will be;... 
Meaning of the word marked with <WSD> tags:  To engage to serve on board a vessel.