Mr. Keetch is the second mate on the Seahawk. He's nervous and fidgety and kind of gives Charlotte the creeps. Zachariah and Charlotte plot the second mutiny with Keetch, but they don't realize that old Keetch has actually been in cahoots with the captain this whole time. (Probably, as Zachariah tells us, because he was being blackmailed.) It's Keetch's voice speaking with the captain that Charlotte hears as she falls asleep the very first night on the ship (2.102).