Moby-Dick Questions Epilogue: How do you read symbolism of the vortex

How do you read symbolism of the vortex, and what symbolism do you read into Ishmael’s being held afloat by Queequeg’s coffin?  If you know who the biblical Ishmael and Rachel are, how is it both ironic and meaningful that Ishmael is saved by the Rachel?  Does the voyage regenerate Ishmael?  How is he different at the end of the novel than at the beginning?  You might try rereading ch. 1 after finishing the epilogue.