Raft is an excellent sea survival simulator. Here you will have to saddle a real raft and make a full-fledged housing out of it, in which you can live, survive, and at the same time travel through the endless expanses of the sea. The whole world went under water, and you, as one of the few survivors, ended up on a raft. So you escaped death and survived. But then it will be more interesting  you will have to travel on your raft through the endless sea waters, dive under the water and get various items there, build and complete your raft, equipping it with new decks and everything you need to survive. Under water you will find everything you need during your trip.