Open Water (2003)

Daniel Kintner and Susan Watkins are frustrated that their hard-working lives do not allow them to spend much time together. They decide to go on a scuba-diving vacation to help improve their relationship. On their second day, they join a group scuba dive. A head count is taken and the passenger total is recorded as 20. Daniel and Susan decide to separate briefly from the group while underwater. Half an hour later, the group returns to the boat; two members of the group are inadvertently counted twice, so the dive master thinks that everyone is back on board and the boat leaves the site. However, Daniel and Susan are still underwater, unaware that the others have returned to shore. When they resurface, the boat has gone. They believe that the group will soon return to recover them.

Stranded at sea, it slowly dawns on Daniel and Susan that their boat is not coming back for them. They bicker, battle bouts of hunger and mental exhaustion and realize that they have probably drifted far from the dive site. They also realize that sharks have been circling them below the surface. Soon, jellyfish appear, stinging them both, while sharks come in close. Susan receives a small shark bite on the leg, but does not immediately realize it. Daniel goes under and discovers a small fish feeding on the exposed flesh of her bite wound. Later, a shark bites Daniel and the wound begins to bleed profusely.