The sharks had been following Captain Roger Schmall's Christie Nicole for days, feasting off the refuse from the boat's shrimping operation.
The sharks eventually became aggressive and, according to the captain, began attacking the boat. And once a big 14-footer took out the ship's propeller, the crew found themselves stranded and sinking.
"It's pretty scary when you're sitting there and you got all that water coming in," Schmall told the Associated Press.
Editor's update: The maximum published weight for a bull shark is about 700 pounds with a length of more than 13 feet, according to fishbase.org. However, a bull estimated to weigh 1,000 pounds was caught and tagged last year (2012) in the Florida Keys.