The beginning of the end,
the end of space and
the start of eternity.

What is it?

What does not have weight but is able to let a ship sink?

At a nice sun shiny day, a man rowed with his boat to an island in the middle of a big lake. On the island he caught some fish. Then he decides to return with his rowing boat. After 10 meters of rowing he looks behind him, but to his big surprise there is no island anymore. What happend to the island?