Starbuck senses that, even though his soul is rebelling against Ahab’s plan for revenge, he’s going to continue supporting and helping Ahab as first mate.
He hopes that they won’t be able to find the whale in the vast ocean. Maybe then Ahab’s blasphemous vengeance won’t be able to happen.
When he hears the men partying down below, Starbuck is alarmed and disgusted by the "heathen crew" accompanying him on this voyage (38.2).
He feels horrified by life and hopes he can fight against the evil things he senses.