Average men are risking their lives for revenge. This is very surfacy, but when you look at the basis of all of this, it is true, and this is madness. Ahab is almost like a mad-man. I believe that there is more to his quest than what is of the surface, but in general his voyage is for purely revenge purposes. The whale is the enemy, but it is just a natural creature, Ahab is not just a natural creature, Ahab is not in his natural environment and this is overpowering.
Human nature is an interesting thing.
Perhaps Ahab's purposes are in a way - natural. Maybe he is not mad, but when looking at the comparisons it is difficult to believe this. The coffin seems to be an intricately detailed piece of wood, but for some reason it must serve a greater purpose than that - for Queequeg and the others. I just thought it an odd request that was so easily complied with. It is obviously important to Queequeg to spend all of his spare time carving out his crazy drawing.