IRONMAN Maryland offers an exciting full-distance triathlon in Cambridge, MD, featuring scenic courses through the Choptank River, Blackwater National Wildlife Refuge, and downtown Cambridge. Swim: The 2.4-mile swim in brackish tidal waters involves swimming against the current outbound and with it inbound. The swim ends at Long Wharf with views of the Chesapeake Bay Lighthouse. Water Temp: 72°F (22°C) Bike: The 112-mile flat bike course features two laps through Blackwater National Wildlife ...