The Dead Sea; one in a million

I took this photo when I went to visit the Dead Sea in Israel. It was my second time to visit the Dead Sea. I joined a bus tour from the capital Tel Aviv just to spend for a half day around the Dead Sea. It was already in November, but still not too cold and I could enjoy floating on the Dead Sea. By the way, I've asked my acquaintance who was born in an English speaking country about the Dead Sea. My question was 'float on the Dead Sea' or 'float in the Dead Sea' which one is correct. He said on and in are correct in this case. Super.