Captain Pugwash: A Pirate Story

I finally (!) found a copy of one of the Captain Pugwash books at Internet Archive, and I read it today.

Captain Pugwash, in this episode of the series, has an offer to transport barrels of brandy on his ship for an outrageous amount of money. But soon we learn that there is not brandy inside the barrels, but pirates, pirates intent on taking over Captain Pugwash's ship. The plot is foiled by the cabin boy, and everything is set aright.

One of the 1001 Children's Books You Must Read Before You Grow Up.