RedactedNarrative: 1988 J 40 Sailboat traveling North bound in the southern branch of the Elizabeth River at the Gilmerton Bridge and the operator  thought he had enough height to get under the bridge.  However, he didn't and the mast struck the steel under the bridge knocking the entire mast off the vessel and it fell into the water.  The red navigation light attached to the bottom of the bridge was also damaged.