When a man jumps from a boat the boat moves?

When a man jumps from a boat, the boat moves in the opposite direction due to the principle of conservation of momentum. As the man pushes off the boat, he exerts a force backward, causing the boat to move forward. This reaction occurs because the total momentum of the system (man plus boat) must remain constant if no external forces are acting on it. Thus, the movement of the boat is a direct result of the man's action.