I remember watching a movie with a similar plot to this about 6 years ago, but I cannot remember the title.
Plot: Man moves across the street to a family and ends up stalking them and installing pinhole security cameras into their home from the attic. From the cameras protruding from the ceiling, he watches them but is eventually caught but does not go to jail. Then, from what I remember, he ends up taking the family hostage on a boat when they try to escape and attempts to murder them. I recall the ending being especially good, I believe the killer ends up getting handcuffed to the boat as it sinks or something. I have attempted to Google search this but to no avail.

The ending sounds like Cape Fear, but the rest doesn't match up.

I'll offer this for a starter though I have hazy memories of it:

Night of Terror (2006 TV movie)
Starring Mitzi Kapture, Nick Mancuso, Rick Roberts
IMDb synopsis:
A family divided, a relentless storm, and a killer on the loose. What starts as a week-long boat trip to save a troubled family dissolves into a savage fight to save their lives. An obsessed stalker has tracked Jill Dunne, husband Sean and daughter Olivia miles down a treacherous river. His desire is to claim the Dunne family as his own; but, first, he must get rid of Jill's husband. As darkness falls and the storm rises, the killer approaches with ghostly precision, igniting a deadly confrontation among the hunter, the hunted and nature's fury.

Night of Terror (TV Movie 2006) - IMDb (http://www.imdb.com/title/tt0760179/)

I've been trying to recall movies involving spying and a boat.

I considered this though I don't recall a boat:
Intimate Stranger (2006 TV movie)
Starring Kari Matchett, Peter Outerbridge
IMDb review (edited):
Karen and son Justin have been on their own for six years.. . She doesn't have the best track record with men. Justin's father, Joe, was too controlling and does not live up to his responsibilities. She is now getting flowers with a note saying they are from Randy. Her boss, Alex, seems to like her, but he's kind of young. Now, Karen has found Denis, who is kind and caring, knows how to cook, and enjoys spending time with Justin. So, what's wrong with Denis?. Many strange developments occur: The air conditioning keeps cutting off during a hot summer; there are strange noises in the attic; and there are problems at work, including a mysterious illness. / She later learns that Denis, whom she stops seeing after he becomes controlling, has installed surveillance equipment.