The crew of the German U-Boot are wearing Wehrmact (German Army) uniforms, not Kriegsmarine (German Navy) uniforms.
In the movie, General Omar Bradley is giving commands to the SS Lawton B. Evans. This never happened. General Bradley was in charge of land forces and not the navy.
This movie is set in 1943. General Bradley in the movie is seen with four stars on his helmet. He did not get promoted to a four-star general until March 12, 1945.
There is not about a PT boat and her crew. It is about a merchant marine supply ship and her crew.
Throughout the movie, the ship commander is discussing with General Bradley military plans and strategies over an open radio broadcast for the enemy to hear. Such a huge lack of security would never have occurred in reality.
E. Roberts wears modern Ray Ban spectacles.
When the sailors are firing their machine guns on deck, there is no recoil when fired.
A U.S. flag seen in the background in a few scenes has the present number of 50 stars, not 48 stars at the time of the second world war.
the coffee pot in the mess shown is a modern drip pot.
An overweight Gen./Maj. Gen. Bradley is wearing a 1970s-1990s green US Army class A jacket with some sort of weird yellow stripe on the sleeve, and four big dumb plastic-looking toy stars not centered on the front of his helmet. Not only are these incorrect, but he would not have been wearing a helmet with Army office attire.
At 18:40 mark, a cast member states: "The moon is not going to rise for a couple of hours, the bastard will never see us." It is clearly daylight.