Continuity mistake: In the scene where McHale rides his motorcycle out of the boat, the machine gun on the aft deck is off center (so he can drive past it). The rest of the time it's on the centerline of the boat.
Continuity mistake: When the cuban cop arrests the guys, he's on the phone and when he hangs up the phone he states that these 4 American Navy guys are going to allow him to see President Castro. He makes the statement and then sits in his chair and puts his cigar in his mouth. The camera angle changes to McHale who is looking in the window and we see the cop sitting down and putting the cigar in his mouth again.
Continuity mistake: This actually occurs several times throughout the film. Vladikoff has a very interesting speedboat. Not only is it fast, not only is it stealthy, but it actually generates new missiles. In the scene where McHale is at home, and again in the scene where Cobra is flying in, Vladikoff fires a missile, yet the very next shot shows the launch rack with two missiles. (01:40:00)
Revealing mistake: When Captain Binghamton is giving his pre-invasion speech, the camera pans back and past a machine gun. The cartridges in the belt are just casings with no bullets in them.