On 8/6/2011 at approximately 1915 hrs Conservation Officer recieved a phone call from the Mahaska County 911 Center.  The 911 operator advised CO that 2 boats had collided on the Des Moines River near 1528 280th St on the north side of the river.  The 911 operator advised that one of the boats had sunk and that several individuals were in the water.  CO responded to the scene and upon arrival was advised by Mahaska County deputy sherrif that all persons were accounted for and all were out of the water.  

(vessel 2) was approaching (vessel 1) from the rear and overtaking it on the starboard side.  Vessel 1 was traveling at approsimately 25-30pmh and vessel 2 at a greater spped.  As vessel 2 came along side of vessel 1 , both operators were startled at the close proximitiy of each other and vessel 1 operator turned sharply to the port side and vessel 2 turned to the starboard side in an attempt to avoid a collision.  The vessels did infact collide with vessel 1's starboard rear striking vessel 2's port side, punching a large hole in vessel 2, as well as ejecting 2 of vessel 2's passengers.  Vessel 2 sank within seconds.  Vessel 1 remained at the scene until all passengers were accounted for and safe, then left to find the 3rd boat in the party.  They were unable to retrieve the sunken boat.  No injuries were reported.