Fortnite players get confused when trying to log into the game, as instead of the usual game menu, all they can see is a small version of themselves floating in a vast ocean. There is no option to play the game and there is no indicator of what is happening.
This strange event is actually the result of the end-of-chapter event that unfolded in the game just a couple of hours ago, on December 4. After the Queen of the Cube attempted to open a portal that would allow a large force of alien motherships to invade the island, the Foundation appeared to put an end to her plans.
To do this, he had no choice but to turn the island entirely, submerging it in the sea, interrupting his attempts to channel the large amounts of energy needed to maintain the portal. This caused it to explode, the portal closed and cut off the invading force, and eventually the island was completely flipped over and crashed into the sea.
This revealed an entirely new map on the other side that players will be able to explore in Chapter 3 and also caused a massive tidal wave to crash into players who had survived the end-of-season event. Now, they are floating unconscious in the ocean, waiting for the servers to come back online. So until all the backend work is complete and we can log back in for the new challenge, any player who logs in will be found floating unconscious in the ocean.