RedactedNarrative: Vessel one (herein V1) was operating eastbound from Capt. Resort dock to the Intracoastal Waterway channel when it struck a submerged object later determined to be an underwater dredge pipe.  V1 was then docked at the Sebastian Inlet Marina. V1l was later hauled out of the water and the damage was assessed to be approximately $3,500. The cause of the accident was determined to be operator inatttention as the submerged dredge pipe had been well marked. Also, a warning was issued to the operator for failure to report a boating accident.