Employees were trying to get the cable to the dredge by pulling the rope through the shackle. Coworker 1 gave the green light to coworker 2 to put tension on the rope. As they put tension on the rope, injured employee ran to the front of the boat to get the knot through the shackle. As coworker 1 told them to move their hand, the tension had already pinched their finger.