RedactedNarrative: Vessel 1 picked up several persons from shore, bringing the total aboard to 9 Occupants.  Vessel 1 was rated for 1100 pounds people and equipment; with all persons on board, the weight was approximately 1800 pounds.  Vessel 1 then anchored, at which time one of the Occupants entered the water to swim.  Shortly thereafter, the remaining Occupants aboard Vessel 1 noticed water in the vessel.  The group pulled anchor, bright everyone back on board, and started toward shore.  Vessel 1 sank as water came over the back of Vessel 1.  The Operator decided to swim to shore at this point, swam as far as a nearby buoy, and held on to the buoy.  The Victim left the boat and started to swim toward the Operator.  The Victim then yelled for help and disappeared. 
  
  Investigation revealed that the ventilation intake on Vessel 1 had been modified.  The cover and hoses leading to the bilge area had been removed, allowing water to enter Vessel 1.