RedactedNarrative: Vessel #1 was operating on Lake St. Clair at approximately 20 mph southeast of the Clinton River.  Vessel struck a partially submerged pipe causing damage to his hull, tearing off one outdrive and damaging his second outdrive.  Vessel took on water and was towed by Tow Boat US.  The pipe in question extended from a barge conducting dredge operations approximately 1/8 mile off shore to a marked construction operation onshore.  Site is marked and USCG has broadcast warnings regarding operations there.  No injuries were reported.