In Chapter 36 of Moby Dick, Captain Ahab calls the entire crew together on the quarter deck and makes the following announcement:
"All ye mast-headers have before now heard me give orders about a white whale. Look ye! d'ye see this Spanish ounce of gold?"--holding up a broad bright coin to the sun--"it is a sixteen dollar piece, men. D'ye see it? Mr. Starbuck, hand me yon top-maul."
This is an immense sum of money for the times, and the beautiful gold coin fascinates all the assembled men. Ahab proceeds to nail the coin to the main-mast and tells them:
"Whosoever of ye raises me a white-headed whale with a wrinkled brow and a crooked jaw; whosoever of ye raises me that white-headed whale, with three holes punctured in his starboard fluke--look ye, whosoever of ye raises me that same white whale, he shall have this gold ounce, my boys!"
An ounce of gold at the present time would be worth in the neighborhood of $1200.
This scene in Chapter 36 serves to demonstrate Captain Ahab's strong motivation and also to show how his motivation is projected to all the other men aboard the ship by means of that gold doubloon. At the same time, Ahab's speech serves to identify Moby Dick out of all the other whales in all the oceans. Moby Dick is a white-headed whale with a wrinkled brow and a crooked jaw. He has three holes punctured in his starboard fluke. Whales have triangular-shaped tails. Each side is called a fluke. The starboard fluke would be the right side of the big tail. In nautical terms the left side of a ship is the "port" side and the right side is the "starboard" side. Ahab is being rather quaint in calling Moby Dick's right fluke his starboard fluke, but it serves to characterize Ahab as a sea dog, a man who has spent most of his life at sea and knows the sea much better than he knows the land.