Deceased victim was with a group of friends.  While the boat was drifting, all jumped overboard to swim.  The victim was the last to depart and jumped feet first in the water.  About five minutes after he entered the water, his friends noticed that he wasn't around.  They swam back to the boat, anchored it and called for help.  There was a small craft warning, seas were rough and wind moderate.  The victim's father indicated the victim is not a good swimmer.
Howell Pt