RedactedNarrative: Vessel number 1 with 2 occupants was cruising at a speed of approximately 30 mph when the vessel struck a dredge line under tow, by vessel number 2, in a NO SKI zone. The dredge line was 6,000' in length and partial submerged.  The operator of vessel 1 reports the line was not visible above the water.  The collision with the dredge line resulted in outdrive being ripped from the drive mount and resides on the lake bed.
  
  Two dredge crew members witnessed the vessel begin to sink and assisted the vessel by use of dewatering pump and towing vessel #1 to the Indian Lake campground launch ramp.
  
  The dredge line was submerged at the area of impact.  Orange ball buoys were used to mark the location of the dredge line every 200' while in tow.  An orange ball was reported 20' away from the area of impact.  The collision occurred between Lake Ridge Island and O'Connor's Point at Indian Lake, Approximately 500' from shore.