That will do as well." "Yes, sir," replied Bob, who, not suspecting anything, hunted up the first mate and made his request.
"You'll find it right over there," said Mr.Carr, pointing to a big water barrel on deck.

It was one from which the sailors drank.
"If it's too heavy for you, you'd better get help," said Mr.Carr, trying not to smile.

But Bob was aware now that he had been made the butt of a joke, and though he felt a little embarrassed, he had to laugh in spite of himself.
"That's pretty good," he said.

"A left-handed marlinspike turns into a scuttle-butt, and that turns into a water barrel.

I've got lots to learn yet." He could hear the sailors laughing at the trick they had played, with the consent of the first mate, and with a grim smile Bob resolved to get even..