Just hanging out under water for 20+ minutes, waiting to be saved...
Let me get this straight: the brothers arrive at a traffic jam, which judging by its length is at least 10 minutes along. Then they sit there chatting for another 5 minutes. Then another 5 minutes pass until he sees the helicopter. Then he runs for a while before jumping in the water. All the while, a rescue helicopter and the coast guard have been called. In the meantime, the victims themselves have somehow acquired super-human lungs which enables them to breathe underwater for at least 20+ minutes, just sitting there waiting for the hero to save them?
I actually liked this movie up until this very lame, implausible ending.
p.s. SPOILER