Has to be JAWS – love swimming, and water generally, but since that film I still get horrors in open water when I cant see the bottom.
Couple of years ago taking a 40ft yacht cross channel in a dead calm we motored over a bit of fishing net and fouled our prop.
Stationary with no wind so we couldn’t sail out. We were in the middle of one of the shipping lanes. Radar showed 3 large vessels on intercept, about 4 miles or 10 mins away, each of them might not see us and run us down (one bloke on the bridge and he’s on the loo trous round his ankles, reading the Daily Star). Over the side i went to cut clear the prop.
I wasn’t too concerned about the cold water, the oncoming big ships, or the swell causing the boat to bounce up and down on top of me. I was really worried about 400ft of water beneath me and what might be in it. Damn that film, I never moved so fast and was relieved to be out of the water. And I wet the bed that night and had nightmares for a couple of weeks afterwards.
All purely based on the terror of swimming in open water and that fish 😯
Never been bothered that much by any other film.