Go to the part where the two guys are using the Sunday roast as bait, fishing from an old wooden pier. When the shark takes the bait and starts swimming out to sea, the camera flashes to the chain being run out. To me that was a very long chain. When the shark turns round as if to attack the man that was pulled into the water, the distance doesn't seem that far, well not as far as the chains length anyway! Surely that man would have been eaten long before reaching the safety of the remaining pier!!