Write the character sketch of Captain Ahab.

Ahab is the Captain of the Pequod, a grave older man reaching his sixties who has spent nearly forty years as a sailor, only three of which he has spent on dry land (Melville alludes to Ahab as having a wife and son, but their existence seems of little significance to Ahab). The novel is essentially the story of Ahab and his quest to defeat the legendary Sperm Whale Moby Dick, for this whale took Ahab's leg, causing him to use an ivory leg to walk and stand. Ahab is a dour, imposing man who frightens his crew through his unwavering obsession with defeating Moby Dick and his grand hubris. In many respects Melville portrays Ahab as barely human, barely governed by human mores and conventions and nearly entirely subject to his own obsession with Moby Dick. Melville describes him in mostly alien terms: Ahab is a spectral figure haunting Stubb's dreams and existing in a place away from the living. He is in some ways a machine, unaffected by human appetites and without recognizable emotion. And most importantly, he claims himself a God over the Pequod, but instead he may be a Satanic figure through his somewhat blasphemous quest against the white whale.