When the team jumps out of the plane at the beginning of their mission it is clear that they're all wearing ground combat gear, as can be seen from the first shots of the free-fall. However, when they splash down they're all wearing scuba gear.
As the Seals swim out for their rendezvous with the submarine, one man can be seen wearing swim fins on his feet. Even if he had carried these with him throughout the mission, he did not stop to put them on while being chased and shot at by terrorists.
When the SEAL team jumps from the helicopter, off the coast of Lebenon, they push a deflated and folded up rubber raft into the sea. You next see them in two inflated rubber rafts, each with very large outboard motors on the back of them.
When Hawkins jumps off the bridge, Curran backs up his Jeep to toss the shirt over the bridge. He gets up to the camera and the passenger side taillight lens is clearly broken off. In the next scene where the men leave the church, Hawkins gets dropped off and the guys leave in the Jeep, with the taillight intact. Since Hawkins gets dropped off soaking wet, and since Curran had to get ready for the wedding, there was no time to get the light fixed. The broken taillight reappears as Curran arrives at the restaurant.
When they are on the way to the wedding, crossing the bridge, the right rear tail light lens on the jeep they are riding in, is broken. However, when they leave the wedding early, the right rear tail light lens on the jeep is intact.
During the flight from Cyrpus to Lebanon, just 250 km ESE of Cyprus, the sun keeps changing position. In many of the scenes the sun is on the horizon forward and slightly on the port side of the aircraft, meaning the sun is in the east (dawn). When the rear door opens the sun is astern, i.e, in the west (dusk).
When the SEALs are leaving the seaport with the rescued helicopter crew we see them pause at the bottom of a set of stairs before crossing a narrow lane way. When the camera pans to the roof we see to holes in the concrete slabs on top of the roof. These holes appear when the team sniper, Dane, shots two terrorists behind them. However, this does not happen until about 2 minutes after we see this original screen shot of the team crossing said lane way and they are compromised.
At the beginning of the movie when the men are traveling over the Berkely Bridge on their way to the wedding at Christ's of Saint Luke in Norfolk, Virginia, they are actually heading towards Portsmouth/Chesapeake, Virginia. Christ's of Saint Luke would be behind them, so they are headed in the wrong direction.
When LT. James Curran is talking with Claire in her hotel room at Quality Inn and Suites on Atlantic Ave in Virginia Beach, you can see Navy piers with ships outside her window. Off the shore of the VA Beach oceanfront there are no piers with ships. These piers were at the Norfolk Naval base over 25 miles away.
During Graham's Wedding the team is paged out to go out on a mission thus ruining the wedding. Every Navy Seal team is put on rotation so they know more or less when they are going out on a mission. Any Navy Seal team member will know this ahead of time, so he would not schedule his wedding around the the same time he's on rotation.
As the Seals escape through Beirut in a hijacked car, Leary carries a Stinger missile but doesn't use it until he has figured out how it works. The Seals regularly train with all types of US weapons and any Seal would be very familiar with the Stinger and its method of use.
In the scene where Hawkins chases down a rollback tow truck that has his car, it shows him climbing aboard while it's moving down the road and operating the bed to get his car off of it. This simply isn't possible-the trucks are equipped with a power-take-off that required the transmission be in neutral and it's operated by levers that control hydraulics and not controlled by an electrical switch box. What is more, Hawkins would have had to winch out the cable slightly because you must have a counter-chain at the other end of the car to hold it in place on the bed of the truck or it'd likely fall off.
Before the Seals parachute into the waters outside Lebanon, their planes take off from a base the on-screen text says is in "Northern Cyprus." Northern Cyprus has been controlled by Turkey since 1974 and does not have any American bases.
After Hawkins steals his buddy's date, it shows him driving his car down on to the beach-this simply isn't allowed in Virginia Beach where this scene was shot. Not to mention the fact that for the Lt. to drive from El Gardinos, the restaurant where they were having dinner to Little Creek or NOB, it would have taken a lot more time because it's on the other side of town.
After the SEALS jump from the plane and HALO into the water, there is a scene where two SEALS approach each other and give the thumbs-up sign. This is not a goof, but recreational divers may think it is. In recreational diving, thumbs up is almost always a sign which means "go up" (surface). Recreational divers circle their index and thumb with the other three fingers extended to show an OK sign. SEALS are not recreational divers and may use thumbs up as an OK sign.
When the RPG is launched at the water where the SEALs are swimming in, a blue circle is visible, marking where the rocket is to hit the water (and, presumably, where the detonation of the explosive charge is to go off).
The goof item below may give away important plot points.
At the end of the movie when the Seal team is swimming out from the beach to escape, there are a number of enemy soldiers firing at them from the beach. The Seals dive under the water to avoid being shot, but the angle at which you see the bullets coming down under water cannot be achieved from firing from the beach into the surface of the water at that distance. For those bullet angles, the shooter would have to be several feet above the surface, at a range of mo more than 10 feet from the bullet entry into the water.