Character mistake: In the training room, after Randall is discussed as the record holder, the students are brought to attention. All but one is standing at attention, he is in the back on the right hand side, standing at ease.
Visible crew/equipment: Above Helen's head the first time Ben telephones her a boom mike is visible.
Factual error: When the new candidates report in to Rescue Swimmer School, one of the airmen is wearing the Silver Star ribbon. The person is too young to have served in another service, and there are no other service's ribbons worn - and the Coast Guard hasn't issued a Silver Star since Vietnam.
Suggested correction: Nobody is wearing medals except for the captain and Randall in the entire scene.
Audio problem: When Randall walks into Maggie's Hanger for the first time in the film, Maggie is singing. As she goes to greet Randall she hands her microphone to a backup singer to take over, who can be heard taking over the singing, but she doesn't use the microphone for a few seconds.
Continuity mistake: When Fischer was quickly getting his clothes on to get to base after he spent the first night with his girlfriend, he put a shirt on, and then in the next shot he didn't have a shirt on and he put the same shirt on again.
Factual error: It is mentioned that Ashton Kutcher's character was offered swimming scholarships by all the Ivies. Not only do Ivy League schools not give athletic scholarships, but seeing as Kutcher's character hasn't swum competitively since he was a sophomore, it is highly unlikely they would have recruited him at all.
Continuity mistake: When Kevin Costner arrives at the diving school, there is a board on the wall containing a list of base records where Costner's character owns all bar one. In a later scene at the swimming pool, Costner brings a board which lists the base records where Costner now owns them all.
Continuity mistake: When the new recruit and the teacher go into the water together, for a rescue, at one stage, one of them is going straight ahead to the cave, like he's supposed to, but the other one is heading right, which is completely wrong; but then, somehow, they're together again.