RedactedNarrative: Vessel A left Buckshot Bay and headed NW up the Calamus Reservoir.  Vessel B left Homestead Knolls and headed WNW up the Calamus Reservoir.  Both vessels were headed to approximately the same location.  Both operators advised they were going 20 - 25 mph.  Vessel A operator didn't see Vessel B until after the collision.  He advised that at first he thought he hit a stump or an anchored vessel.  Vessel B operator  didn't see Vessel A until his passenger yelled that another vessel was about to hit them.  Vessel A hit Vessel B forward of the console on the left side.  Vessel B operator and his passenger advised that after Vessel A hit Vessel B, it spun a circle and hit them again.  They shut off Vessel A and held it while they helped the Vessel A operator out of the water and back on to his boat.