Continuity mistake: When Mike is repainting a striped beach-house, he turns to see his friends riding a catamaran, and he then turns and makes a big splodge with his brush on the second stripe from the side, on the beach-house. In this shot note the shape of the paint on this stripe. After Chief Brody rings the bell because he thinks he sees a shark, he begins to climb down the watch tower, and it then cuts to a shot of Mike standing in front of the beach-house - and now the shape of the paint-marks are different - they are lower and smaller. (00:42:35 - 00:44:50)
Continuity mistake: In the scene where Brody drives his jeep onto the ferry he drives it to the edge. Yet in the next shot when it reaches the other side the jeep is about two feet from the edge.
Continuity mistake: In the shot of Eddie falling backwards out of Tina's Joy into the water, his hair is wet before he hits the water. (01:10:15)
Continuity mistake: When Brody walks up on the old lady's porch and Tina says "We heard this noise like a boom", Brody has his hands hanging down. When it cuts, he has them up. (00:22:40)
Continuity mistake: When Terry is water-skiing, her mum is driving the speedboat. The speedboat has the writing "MS 5713 EB" on both of its sides. The sides of the boat are made up of shiplap boarding. In the first half of the skiing scene when we see the side of the speedboat, the writing is printed on the second board down from the top of the boat. However in the second half of the scene, after Terry has been grabbed by the shark, the writing has moved up onto the top board. The condition of the paint of the actual whole boat changes between a few shots too. Sometimes the green paint is totally fresh and new looking, in others it is faded and looks more worn. (00:18:40 - 00:20:25)
Continuity mistake: When Mike says Sean can't come with him, Tina says, "He can help me, at least" with her hair hanging over her right shoulder. When it cuts, her hair is pulled back. (00:12:10)
Continuity mistake: At the beginning of the movie, when the divers find the Orca boat, there is a plate with the word "ORCA", nailed to the front of the boat. However in the first movie this wasn't here. Also, the damage done to the Orca is noticeably different. (00:02:00)
Continuity mistake: At the beginning of the film when the shark attacks the divers, you see in one shot that the shark already had a burned scarred face. The shark doesn't get set alight until later in in the film. This scene was one of the last ones to be filmed.
Continuity mistake: After explaining what they saw when Terry's mom's boat exploded Tina asks if they can leave. Brody then puts his hand on the porch column on the left side of it. When it cuts his arm is resting on the right side of it.
Continuity mistake: When Hendricks enters Chief Brody's office with the diver's camera, the camera is old and a very dark brown. The middle circular lens has an inside light bulb-fitting and the large black torch attached to it is worn and slightly damaged. However, in the shots of Hendricks saying "Dance?", he is holding the same camera but it is clearly different. The camera is lighter in color, the inside light bulb-fitting from the middle circular lens has vanished, and the black torch is newer-looking. (00:15:10)
Continuity mistake: At the breakfast table when Sean says "I want Fruit flakes" he has a glass of juice and a glass of milk in front of him. When it cuts, the two glasses switch places. (00:25:10)
Continuity mistake: When we see the dead whale's mouth there is some seaweed on its mouth. When Brody is helping Dr. Elkins measuring the whale a larger lump of seaweed appears on its mouth. (00:27:35)
Continuity mistake: The pilot in the rescue helicopter wears no sunglasses as he is about the take off. But when the shark is attacking the copter, sunglasses briefly appear on the pilots face in one shot, then vanish. (01:28:15)
Continuity mistake: When Brody and Ellen are talking about Mike being seventeen and should have a summer job we see Brody placing his arm on the side of the door entrance. When it cuts to a close-up from behind Brody you can see he has lowered his arm so the camera can get a clean shot of Ellen's face. When it cuts he has his arm back up. (00:25:40)
Continuity mistake: When the teenagers are near Cable Junction on their wrecked boats, they see Chief Brody coming towards them on the Police Boat. We then see a close-up of Brody, and from his view he is approaching Cable Junction and the teenagers from front-on, with the teenagers on the right. When we see Brody approaching them as seen from Cable Junction, he approaches them from a completely different direction. He comes from behind them as if he approached from a different side of the island.
Continuity mistake: When Eddie gets the blanket out of the wooden box for Tina, there is a large board of wood sticking out of the wooden box. In the next overhead shot it has vanished. (01:10:10)
Continuity mistake: When Eddie gets the blanket out for Tina, on the small "Tina's Joy" boat, the sail jumps from being on his left side, to his right side suddenly, between shots. (01:10:10)
Continuity mistake: In the scene where Chief Brody comes home drunk, Deputy Hendricks comes over to express his sorrows. When he's leaving/already left, Both Ellen & Chief Brody comment on Hendricks as "Poor Jeff." In the first Jaws film, Brody calls him Lenny. Jeff is actually the first name of the actor who played Hendricks.
Suggested correction: It was a retcon from the filmmakers. Originally his name was Lenny, and then they changed it to Jeff. Same thing with The Mayor's children in the first movie. In the sequel, he only has one son; Larry Jr.
Not really a retcon, simply a mistake. Not every change, intentional or not, can be hand-waved away as a retcon.
The correction is valid. The person who submitted the mistake didn't watch the scene. They never said "poor Jeff", it was "poor Hendricks." But both Martin and Ellen call him "Jeff" in the scene and his name is said 3 times. Plus, if you read over the original script, the name "Jeff Hendricks" is mentioned 4 times.
Continuity mistake: When Brody checks Mike's room only to find out he's not there, Brody's shadow on the door changes between the shots. (01:06:50)
Continuity mistake: When Tina is called forth to cut the ribbon, she walks up and stands a few feet in front of the girl in the yellow dress. When it cuts, they have moved closer to each other. (00:06:10)