Continuity mistake: After Goodspeed grabs the pearl on top of the lighthouse, one of the remaining soldiers shoots at him from another rooftop. When he starts firing, he's near the corner of the roof. But, when Mason gets up the roof, the soldier is nowhere near the corner. I don't see why he would switch positions, since moving to the left as he appeared to do would make it harder to hit Goodspeed.
Continuity mistake: When Sean Connery kills the soldier telling Nicholas Cage to get on his knees at gunpoint, Sean Connery takes the rifle and rests the stock on Nicholas Cage's shoulder. In the wider shot when Cage takes hold of the gun, the stock is a slightly different style than the one that was on his shoulder.
Continuity mistake: When they fire the missile, they say its headed for the game in Oakland. The tracking computer shows it heading for the Oakland Coliseum but when its diverted it shows it was about to hit Candlestick park in San Francisco.
Revealing mistake: Towards the end while Goodspeed is struggling with the last soldier, then he jumps down and the stunt double is visible - the hair is different.
Continuity mistake: When Mason pulls Goodspeed out of the water in the next scene they are both completely dry hair, clothes, face but when Goodspeed is picked up his hair, clothes and face are wet.
Continuity mistake: When Sean Connery breaks the window with his hand, the shape of the hole in the window changes between shots.
Continuity mistake: In the beginning of the movie as Hummel visits his wife's grave, the rain changes from shot to shot, in some it's raining heavily, while in others barely at all. In the shot just before we see who's grave it is you can see blue sky behind Hummel.
Visible crew/equipment: Right near the very end where you have the overhead shot of the bombs hitting the back of the island you see Stanley Goodspeed being thrown through the air by the force of the explosion, and into the water. As he is flying through the air you can see the wires he is attached to, to make him fly.
Visible crew/equipment: In the interrogation room, it shows the mirror reflecting Mason, Goodspeed and the other guy. Look carefully: for a split second you can see a shine of a watch, then an arm, of the cameraman.
Character mistake: When Captains Fry and Darrow are advising General Hummel to launch the rocket, Captain Fry says "Let's be all we can be." This was the slogan for the United States Army, but repeatedly throughout the film the men are called Marines which are the United States Navy. A Marine would still never use the Army's slogan.
Suggested correction: He's just making a statement. He's not saying he's in the Army.
A Marine would still never use the Army's slogan.
Continuity mistake: The SEAL Team attempts to take the island in the cover of night. When Hummel expects invaders, he sends out patrols to look for them. In every shot of the patrol searches it is night. Except for one shot where it is pure daylight.
Continuity mistake: When Goodspeed is driving through the warehouse in his yellow convertible then smashes through the big glass window you'll notice that it's simply not possible. The window is about a foot off the ground, which means there would have to be a ramp. If you look closely there are two hinges at the bottom of the window which show where the ramp ends. The fact that there's a ramp at a dead-end window was poorly planted there by the crew.
Deliberate mistake: When one of the captains throws the grenade while Mason is in the bath, it coincidentally rolls to a left into the bathtub area, instead of rolling straight.
Suggested correction: The grenade isn't a sphere. It is obviously lopsided, and would tend to not roll in a straight line. Although it is probably exaggerated for the scene.
