Dad Overboard

From the introduction:

Just as their meeting is ending, the Mavens are approached by Brindlewood County’s chief law enforcement officer, Sheriff Wyman Dalrymple. He tells them that, several nights ago, a wealthy financier, Albert Krause, was dragged out of the bay, dead. Mr. Krause and his family were on a yachting vacation and their boat is presently anchored a quarter mile from shore. The surviving Krauses—wife Amanda, eldest daughter Sara, son David, and youngest daughter Emily—assert Mr. Krause was drunk and simply fell overboard. Sheriff Dalrymple suspects foul play but hasn’t been able to turn anything up. The body is currently being held in a cold storage at the fish market until it can be shipped back to Boston for the funeral.