Trailer here.
The Film begins with a couple who get attacked by something in the water. Cut to Charlie(Jakubenko) and his girlfriend Kaz(Bowden) who run a charter service bringing people around to islands in their seaplane. They get a booking. It is a married couple, Joji(Kano) and his wife, Michelle(Tsukakoshi). They want to go to a place called Hell's reef. Charlie and Kaz bring along Benny, who is a cook. Charlie was a marine biologist but he got bitten by a Shark and this turned him off the subject. The group land on the island and find a dead body. It is one half of the couple from the start of the film. Charlie realises that the person was killed by a shark. They find a phone and look at pictures of the couple and their boat. They go looking and they find the boat. It has capsized and Benny goes inside for a look. There is a dead body in there. A shark comes out of nowhere and attacks them. The sea plane starts to sink. They get onto a raft. Michelle drops a paddle into the water and Kaz goes to get it.