RedactedNarrative: At approximately 0800 on 1/16/2016, One operator and one passenger launched a small, 2-seat, tri-hull plastic craft from the State Route 73 Great Miami River ramp located outside of Trenton, OH to hunt waterfowl.  At about 0815, approximately 1/4 mile downstream from the ramp, the operator state that "for no apparent reason" the small craft capsized near the east bank of the river.  Approximately 1/4 mile downstream of the ramp.  Both the operator and passenger were able to swim to shore with no injuries. Operator then contacted the Butler county OSP post. The passenger account stated that prior to capsizing, the front of the boat rose up and felt the vessel hit or slide over a submerged object. at about 0930 unit #4125 and I were notified of the incident. After conducting an interview with the operator, #4125 and I conducted an on-the water search of an approximate 3 mile area downstream of the ramp. Debris (To include: Vessel seat/hunting  blind/misc. gear) was located in a strainer halfway downstream of the ramp and the Defunct Americana (Lesourdsville) Amusement Park (See incident Diagram).  At approximately 1430 we concluded our river search/recovery effort. Butler County SO and OSP were notified of the last know location of the lost vessel, and the 2x unsecured loaded shotguns that had been sitting atop the vessels deck. All recovered itmes/gear were returned to operator. 
  
  Stream gauge reading in cubic meters per second (6.3 Kcfps = 178.40 cmps)