Why Does Boat Floats In Water?

Boat is a non living thing and it floats on water. For every action there is an opposite and equal reaction. This is third law of newton.
Boat's weight apply force downward and water reacts against it. Water holds it and applys an upward force. This makes the boat stay at its position.
But living things sink in the water. Like a human being. You have to hold your breath or you must be a good swimmer if you do not want to sink into water.

Actually, the weight of  boat can't replaces the water in the lake or sea or ocean.. Thats why it floats on the water.. This will comes under the application of ARCHEMADES principle.