All three objects weigh the same. The weight arrow is the same for all three. The candycane legend shows the amount of water each object displaces. The cube sinks. It sinks because it does not displace very much water. The weight of the displaced water is not enough to overcome the force of gravity (the weight). BF<WT The ships float. They are able to displace a lot of water. Notice that the second ships sits slightly lower in the water and more of the ship is under water in order to displace enough water to float. BF>WT So, the ships sink until they float.

The BF on both ships is > OR EQUAL TO the WT of the ships. This is why the ships float. BF > WT The BF on the cube is < than the WT of the cube. This is why the cube sinks. BF< WT