Question for fans of movie Jaws?

When Quint's boat, The Orca, headed to sea, it had five barrels. One barrel was put in the shark. Shortly after that, I believe, the shark bit through the line when they tried to collect it. They then put three more barrels in it and at the end there was two barrels left. That's six barrels. Did I miss something? Did the first barrel end up back on the boat or did Spielberg screw up the count?