May 10: TriColumbia will hold the inaugural Choptank Bridge Swim, a two-distance endurance open- water swim in the Choptank River, the largest river on the Delmarva Peninsula. The Cambridge event consists of a 1.6-mile swim and a 3.6-mile swim along the banks of the Choptank and between the Choptank River Bridge and the Choptank River Fishing Pier. Registration will be $60 until April 30, then $85 through May 9. Race-day registration, if still open, will be $85. For more information, go to TriColumbia.org or call 410-964-1246.