The writer and director of this awful film obviously have never been to sea. That they can't write dialogue or direct their way out of a paper bag is also evident.
The issue is not food, it is water. You can go two to three weeks without any food and a lot longer if you can catch a few fish. But you cannot go three days without water in those conditions without loss of cognitive function and death shortly after. Also 60 minutes of rowing in a day in an open boat would double your water needs for a day.
Also anyone involved in offshore fishing knows that it is not the distance to land -- but the currents that will or wont take you into shipping lanes that would matter. There are areas (eg where the Malaysian airliner went down) that have no regular shipping for 1,000 miles. But the area where they were is very close to extremely highly trafficked shipping lanes.