Heart of a Samurai by Margi Preus

After all the whaleboats returned to the ship, lamps were lit and the work of butchering began.

Manjiro leaned over the bulwark to watch three men who stood on a platform suspended above the water. Beneath them, sharks tore great chunks of flesh from the whale. The men on the cutting platform jabbed at them occasionally with their spades while they worked at stripping from the whale the thick layer of outer fat called blubber. The huge slabs of thick blubber were winched onto the deck and lowered into the hold.