Jonah was a prophet of the northern kingdom of Israel from the 8th century BC. He is the central figure of the Book of Jonah, and is known for the story in which he was swallowed by a whale. His story is also told in the Qur'an.
Jonah attempts to flee from his duty to God. As a result, God sends a storm that nearly capsizes his ship. Because of this, his name has become a term for someone believed to be jinxed, and therefore dangerous to those around them, especially among seamen.
The command to single up all lines also makes an appearance in Pynchon's novels V., The Crying of Lot 49, Mason & Dixon and Against the Day. Pynchon himself served in the US Navy for a spell.
This is a reference to James Stewart's character George Bailey in the film It's a Wonderful Life. An always selfless character, Bailey lost his hearing in one ear after rescuing his brother from drowning.
It's a Wonderful Life was released in 1946, making this another curious instance of a character in Gravity's Rainbow making reference, either consciously or unconsciously, to something that they should not yet be aware of.