RedactedNarrative: On 07/05/2014 at approximately 1315 hours operator left Las Vegas Boat Harbor piloting the LAKALI LENA  (vessel #1) with 4 additional occupants headed toward Swallow Bay on Lake Mead, Clark County, Nevada. Vessel #1 was traveled approximately 5 miles in a northeastern direction where it entered the outskirts of swallow bay and struck a submerged rock reef. Vessel #1 was traveling at approximately 20 knots at the time of the accident. The rock reef was submerged approximately 2 feet under the surface of the water. The rock reef measured approximately 50 ft by 35 ft. Four occupants were on the bridge of the vessel and one was below deck at the time of the collision. All occupants were thrown forward but no injuries were evident or reported. 
  
  OPERATOR reported that he noticed they were taking on water near vessel #1''s onboard generator. OPERATOR Stated he immediately sent out a mayday.  I, game warden. heard the mayday at 1440 hours and advised NDOW dispatch that I would be responding.  I arrived at the accident scene at approximately 1451 hours.  I advised OPERATOR to turn on his anchor light at vessel #1 would be on the water over night. All five occupants on board vessel #1 were taken on board my patrol vessel at approximately 1456 hours.  Las Vegas Boat Harbor personnel arrived on scene and stated they would attempt to recover vessel #1 the following morning.  
  
  At approximately 1505 Game Warden photographed the accident scene.  At approximately 1506 hours I began transport of vessel #1''s occupants back to Las Vegas Boat Harbor.  I arrived at Las Vegas Boat Harbor at approximately 1523 hours and collected witness statements from all occupants of vessel #1.  I then requested OPERATOR to give a blood BAC sample on my PBT.  OPERATOR BAC per my PBT was .008.  Contributing factors for this accident included dropping lake levels with new unmarked submerged hazards and cloudy conditions reducing visibility for the operator of vessel #1.  Total damage for vessel #1 based on owners statements and Las Vegas Boat Harbor opinions was estimated at $75,000.00. This estimate was arrived upon by taking into account approximately 20 square feet of fiberglass damage, damage to electrical equipment contained within the vessel, extensive upholstery and wood interior damage, prop and drive shaft damage, and salvage fees.