NEWBURYPORT — Andy Kelly had just hooked a 40-inch striper last week when he saw a large, bioluminescent mass coming toward the surface of the water, scaring his catch under the boat.

Then, there was a loud splash, and the fish was gone. 

Although it was after dark, Kelly is sure there was only one explanation: He’d just served up a late-night meal for one of the ocean's greatest predators, a great white shark.

"Not too many sharks would be able engulf a fish that size like that," Kelly said. "It had to have been a great white."

In fact, Kelly, who was on the boat with his father, Ed Kelly, and Zach Pinciaro, said it was the second time the group encountered the massive creature. It first appeared about two hours earlier, shortly after dusk, when Ed had just hooked another striper and noticed the fish's strange behavior.

"It started acting funny, not fighting like a normal striper would, and then it came right at us underneath the boat," Andy said.

Seconds later, a big wake appeared in the distance, suggesting that a large object headed straight for the fishermen's 17-foot vessel. As the wake drew nearer, one of the men quickly grabbed a flashlight and shined it on the water, revealing the outline of what Kelly estimated was a 10- to 12-foot shark next to the hull. 

He said the group watched as the shark circled the boat a few times, looking for its prey before disappearing.

"I thought it was cool to see. It's something that's once in a lifetime, so I was just pumped," Kelly said, noting that in both instances, the boat was in less than 10 feet of water.

Several types of sharks are common in waters near Newburyport, especially in the summer. Great white sightings are more likely further south, on Cape Cod, where they can cause beach closures.

But they are sometimes spotted farther north. This year, experts have detected them off the coast of Maine.

Other local fishermen have had run-ins with sharks this year.

Chris Valaskatgis, who runs Manolin Charters out of Newburyport, said he has seen "quite a few" sharks recently, and he recounted another striper fishing experience off Plum Island.

"We hooked one right near the boat, then out of nowhere, this huge shark took the fish," he said. "He got my hook and ran off and we lost the fish." 

Valaskatgis, who has a lot of shark-fishing experience, said the predator was "100 percent" a great white, adding that it was "about 9 or 10 feet, and it was thick." 

Two days later, Valaskatgis said he spotted two mako sharks in the water nearby, notching three shark sightings in three days.

Valaskatgis said in of all the encounters, he "got less than a splash," and he feels no reason to worry about the sharks' presence. 

"I've seen white sharks my entire life, and I know a few guys who have seen them in other locations …, " he said. "It's exciting for sure. It's good to have some variety."

Jack Shea writes for the Daily News of Newburyport. He can be reached via email at Follow him on Twitter @iamjackshea.