It's a horror movie from the 70s about a blonde haired guy who finds a magic charm bracelet/necklace that links him with a giant turtle. The turtle has the charm/rune /whatever from the necklace carved or printed on its shell. The turtle, about the size of a small car, periodically appears to kill people that the guy is mad at (I think). The turtle later winds up killing the guy's best friend, a black guy who falls off of the boat they are on and gets tangled in some lines or nets, then the turtle appears. The blonde guy may have been some well known actor of the time from movies or tv. I thought it was Mark Hamill or Clint Howard, but no films they were in match. I remember seeing it on ABC one night in the late 70s or early 80s. It reminded me of one of those Jaws rip-offs of the time like Tentacles or Orca. Sorry I don't remember more, but you guys have come through before.
Never mind. I'm an idiot. A little more looking revealed that I was looking for The Bermuda Depths. Now that I know what it is and how hard to find it is, I want to see it again even more.
Is it "Dream of the Blue Turtles???"...oh, wait...thats a Sting album.