Ishmael says that most historical pictures of whales are inaccurate to a whaler who sees whales every day.  He says the only solution to this problem is that if someone wants to know what a whale looks like then to come to encounter one.  He says that only portion of the whale are visible at once, seems how most of the whale is under water, but dead whales are completely visible.  He compares a dead whale to a wrecked ship.  I thought that was pretty funny.