The crew of the steamboat is varied. Their are several men accompanying Marlow on this journey. There are several white men, pilgrims, and several black men. There are also a cannibals aboard the ship.
Marlow is most disgusted with the behavior of the pilgrims as they continue and travel through the jungle. They have no respect for anything except their own sense of superiority. As they bury Kurtz, Marlow observes that he believes that they would like to bury him as well.
Marlow is most impressed with the behavior of the natives, in relation to their restraint. When attacked by the "savages in the fog" the white men panic and fire blindly into the jungle, aiming to high to hit anything and essentially accomplishing nothing. The natives maintain their composure. The same response happens when faced with Kurtz' men. The white men act with great fear and the natives remain calm.