RedactedNarrative: Unit 1, while under sail, was heading out of Charleston Harbor seaward and approached Unit 2 (stated to be a dredge barge) that was coming into Charleston Harbor.  Unit 1 and Unit 2 came in contact port side to port side.  Operator of Unit 1 stated that the steering of the sail became inoperable right before contact.  Operator of Unit 1 attempted to start up the engine to pull the vessel away from Unit 2/  Unit 2 continued moving and never stopped.  No information was retrieved from Unit 2.