When the surviving character crawls out of the water, you can see hand prints in the sand, likely from previous takes of the same scene.
Near the end when one of the characters is crawling out of the water, you can see hand prints in the sand where someone has already crawled out of the water
Through the entire film none of the women have shoes on, only the men. Yet just before discovering the land mines in the sand Reagan is suddenly wearing black flip flops. Once they start walking the shoes are gone again.
When the Federal Prosecutor goes to retrieve the shark teeth, he stands in water and his shirt is visibly wet. In the next scene, as he rejoins the group, his clothing is completely dry.
The captives have bandages on their wounds before they locate the first aid kit.
Sharks growl throughout the film; in reality, sharks have no vocal apparatus and cannot growl.
One of the characters (the federal prosecutor) claims that he had an "RFID" chip embedded in his shoulder, in case he was kidnapped. RFID chips have a very short range, and would be useless for tracking an individual for the purpose of rescue.
The guy who trapped them all there mentions that tiger sharks can swim into freshwater A tiger shark cannot survive in freshwater it is actually the bull shark that can swim into freshwater.
The chains wrapped around the prisoner's wrists are loose enough to slip off.
Layla effortlessly waves a landmine, which should weigh several kilos, around with one hand with her arm at full extension.
Worst CG with the exploding minefield.
Near the end of the movie when a couple are walking along the beach, you can see power lines and a car/truck moving along a highway on the cliff above the beach.
The final scene, the protagonist notes they are one hundred miles south of Key West. The character says 'ah, they are in international waters then'. Cuba is 106 miles south of Key West, so the location would not be in international waters.