Goofs

At about 70 minutes the survivors see a shipwreck and an island in front of them and yet when the sharks are seen behind them there is nothing but the open ocean in front of the raft.

That is the difference between looking shoreward and looking out to sea. The raft had no front or back so there is no "in front of them" or "behind them". There's just Landward and Seaward.

The cut on Michelle's forehead changes size between shots.

During the movie, the sharks are seen growling in anger in pain. Sharks make no such noises.

When the group first finds the corpse on the beach, Kaz (Katrina Bowden) uses the dead man's finger to unlock his smartphone but dead fingers cannot activate the capacitive sensor of a smartphone to unlock it.

The movie is set in Australia but the seaplane has an American registration number. Furthermore, N31417 was deregistered in 2013.

One of the several reasons for deregistering a plane is if it is exported. Since it's no longer in the US, where it used to be registered, and is now in Australia, it has obviously been exported and not re-registered by the film company that made the movie.

The woman killed during the teaser is knocked off the yacht by the boom into the water. however, when Benny searches the capsized yacht, her body is somehow back inside it.

And somehow the yacht got capsized. When there are two unexplained things, the likelihood is that they have the same root cause.