RedactedNarrative: Vessel 1 was traveling in a north easterly direction up on plane entering the center of Lake Flower from a narrow section of the lake.  Vessel 1 failed to observe vessel 2 which was drifting without navigation lights in the center of the channel.  Starboard bow of vessel 1 collided with the stern on the port side of vessel 2.  One passenger onboard vessel 1 was ejected and was able to swim back to vessel sustaining no injuries.  Two individuals on vessel 2 sustained injuries.