“We’re gonna need a bigger boat.” I can still see Roy Scheider tossing chum into the ocean when that huge shark suddenly lunges out of the water, just inches away from his head. Everyone in the theater (including me) instantly gasped or let out a scream, as popcorn went flying everywhere.

It was 50 years ago this month that the movie “Jaws” first appeared on movie screens nationwide. And not since the shower scene in “Psycho” had audiences reacted with such terror.

“Jaws” was definitely not my first rodeo when it came to heart-pounding movies. Throughout the 1960s and ’70s, I couldn’t get enough of suspense thrillers like “Night of the Living Dead,” “Psycho,” “What Ever Happened to Baby Jane?” “The Birds” and “The Exorcist.”

But there was something about “Jaws” that was different. In those other movies, scared as I was, I remained an observer fearing for the characters on the screen. But from the opening scene of “Jaws,” it felt like everything that was happening on the screen was actually happening to me in real time.

So, what was it about “Jaws” that made it feel so real? Why such a visceral reaction? Perhaps the biggest factor was that swimming at the beach had always been associated with joy and delight. It was a welcome relief from the heat. And who doesn’t enjoy splashing around in the water? All of us could easily picture ourselves in that blissful state. Until …

Those two menacing musical notes came out of the speakers. “Bom. Bom.” And then they repeated themselves, over and over, faster and faster, as utter terror replaced the bliss. Even now, reading what I just wrote makes the hair on my arms stand up.

But “Jaws” might have been just another “B” horror movie had it not been for the direction of Steven Spielberg and the magnificent acting of Roy Scheider, Richard Dreyfuss and Robert Shaw.

There’s a scene on the boat the night before the final showdown, where Robert Shaw delivers a monologue about being one of the survivors of the USS Indianapolis after it was sunk in the Pacific by Japanese torpedoes near the end of World War II.

For my money, that monologue was as good as anything I’d ever read by William Shakespeare, or delivered by Laurence Olivier.

To refresh your memory, here’s just a tiny bit of it: “Japanese submarine slammed two torpedoes into our side, Chief. We was comin’ back from the island of Tinian to Leyte. Just delivered the bomb. The Hiroshima bomb. Eleven hundred men went into the water. Three hundred sixteen men come out. And the sharks took the rest, June the 29th, 1945 … Anyway, we delivered the bomb.”

That speech alone was worth the price of admission. And yet, there was still the small matter of dispatching the shark the following day.

Heart-pounding doesn’t even begin to describe the last 15 minutes of “Jaws.” For those who haven’t seen it, or repressed the memory, I won’t reveal it here. But safe to say it’s one of the most suspenseful and hair-raising endings ever put on screen.

In the years that followed “Jaws,” I would go on to see other thrillers like “Alien,” “The Shining,” “Poltergeist” and “Carrie.” But no movie before or after can hold a candle to “Jaws” for the grip (pun intended) it held on me — and didn’t let go.

If the reason we go to the movies, or get lost in a novel, or attend a stage play is to be transported from our ordinary lives to the more exciting lives of others, “Jaws” is the poster child for that transformation.

It’s now 50 years later, and I’m still looking for sharks every time I swim in the ocean.

And I’ll bet I’m not the only one.