RedactedNarrative: On the above date and time sailing vessel (V-1) was traveling west through the Chesapeake and Delaware Canal.  V-1 was westbound at approximately 7 knots when it struck the Delmarva Central Railroad bridge, which was in the down position. bridge operator confirmed that the required warnings were transmitted over marine channel 13 prior to the bridge being lowered.  V-1''s mast heigth is 62'' off of the water and the railroad bridge is listed as 45'' above the water at high tide.  The point of impact was approximately 10-12 feet down from the top of the mast.  The impact caused the demasting of the vessel.