A long-distance swimmer is recovering after being bitten by a shark while attempting a night swim across the Catalina Channel, officials said. The rare encounter happened early Tuesday near Doctor's Cove off Catalina Island. What we know:The incident occurred around 1:20 a.m. when the vessel Bottom Scratcher, a live-aboard scuba diving boat, left Catalina with the injured swimmer on board. Authorities confirmed the swimmer had set out on a solo attempt to cross the Catalina Channel, a 20.5-mile route considered one of the world’s most challenging marathon swims. He also noted that channel swimmers are typically escorted for safety: "When they swim the channel, they usually have a follow boat that’s right next to them the whole time.