It's a movie I saw in the 80's. 2 brothers are on a boat. One falls in and can't swim. The other brother (who was jealous of the drowning brother) holds the paddle out for him to grab on but doesn't hold it out far enough, purposefully, and the brother drowns. The remaining brother blames himself and so do his parents. I believe he goes to impatient treatment to try to get help. I know this sounds a lot like "Ordinary People" but I distinctly remember the living brother watching his brother drown and not try to do anything and that doesn't happen in "ordinary people" does it? The boat scene was during the day and I don't believe the weather was bad. Please help!

Sounds like Family Sins (http://www.imdb.com/title/tt0093005/)