Near the completion of Huckleberry Finn, Twain wrote Life on the Mississippi, which is said to have heavily influenced the novel.[1] The travel work recounts Twain's memories and new experiences after a 22-year absence from the Mississippi River. In it, he also explains that "Mark Twain" was the call made when the boat was in safe water, indicating a depth of two (or twain) fathoms (12 feet or 3.7 metres).