Need Help Finding a Movie/TV Show...

[jcarugati]

Hey,

Ok, so this has been racking my brain, but I keep thinking about this movie (or TV show) that I saw and I can't figure out what it is. I only remember like one scene from it, but hopefully it helps.

The Scene:

It's a couple on a nice motor boat in the ocean. Either the girl or the guy decides to go scuba diving and they have a radar set up and to monitor if anything is close by. So as I said one of the couples go down into the water and this huge thing shows up on the radar and starts going right after one of the couples. They have no contact with each other so the person underwater has no idea he/she is in trouble. Anyway, the BIG dot (monster) overcomes the LITTLE dot (girl - I'm actually sure it was girl now) and moves on with the LITTLE dot nowhere to be found. Then, I think the guy in the boat dies. Don't remember how.

ANYONE? Please, this is killing me.

It's not "Jaws 3" or "Lake Placid."