This accident was entered by teh Coast Guard.  According to a news article, a 20-year old man is dead after jumping from a boat to cool off swimming.  Follow up with state authorities revealed that the vessel was drifting.  Even though the vessel had it's anchor deployed, the anchor hadn't caught because of the depth of the lake. The victim was not wearing his life jacket.  http://www.myfoxtwincities.com/story/18887961/crews-seek-missing-boater-in-lake-minnetonka