Possibly, Jude, but what is his motive? If there's no motive (he just did it for fun) then there's a chance that it would be an almost perfect murder. But a husband who kills his wife always has a motive.
Basically, cops solve cases using the MOM method. Motive, Opportunity, and Means. Find someone who has all three and you've probably found your murderer.
Kinesics (not body language, but the interpretation of body language) goes a long way in determing if a person is telling the truth, and a really good detective will pick up on those subtle signs of lying during questioning. It's a science, not guess work.
An accident such as the one you've suggested may as well have fireworks going off overhead saying, "The husband did it! The husband did it!" Detectives would really focus on this guy. If there's a a clue at all, such as an insurance policy then they'll be all over him.
I'm not saying that cases aren't solved because that happens every day. What I am saying is that there is evidence left behind or taken away from every single murder. If the evidence isn't discovered, then that's the fault of the investigators.
Let's say she was cheating. Let's say the neighbors had heard the couple fighting night after night, and the police had been to the residence multiple times. Let's even say the guy had been arrested one time for hitting her, and that he had a gazillion dollar life insurance policy on her.
Now, let's say her slipping overboard on the sailboat really was an accident, and this guy is innocent.
That sort of thing happens. Kinesics works in reverse, too. So do investigations. Sometimes t's best to start out by ruling out suspects instead of trying to find out whodunit.
And, innocent people go to prison all the time, too. Sigh...
Hey, remind me to never go for a boat ride with Jude!
Well, I guess I should add that time is a factor, too. Police departments are so busy they can't devote every single minute of every day working on a single case.
in my novel (i am sweating with), the entire point of the story is who killed a celebrity model? i'm starting with her body being washed up on the shores of the old Hudson river (I love the Hudson). at first i read your question as where is the best place to find a body--i thought well: anywhere where it might be shocking, get the action going, get people to react--