Step 1
The water level we measured shows how much water we put into the container at first.

Step 2
The water level went up, because the weight of the floating wooden block pushed down on the water. When one end was pushed down and released, the block returned to its original position. The block was stable in the water.

Step 5
The water level went up slightly because of the weight of the second coin. When the low end of the block was pushed down and released, one of the coins slipped into the water, and the block returned to its original position with the remaining coin still in place. The block with two coins was not very stable in the water. However, once the top coin fell off, the floating block with the remaining coin looked like the stable setup in Step 4.

Note: Your results may vary, depending upon the size of your block, the type of wood from which it is made, the weight of your coins, and where your coins are placed on the floating block.

Step 6
The wood block tipped over immediately and came to rest floating with the coins beneath.

In this configuration, the coins are like the keel of a sailboat. The extra weight low in the water creates a very stable situation.