It will probabably have a certain amount of permament ballast inside it, but as you say, she is riding very high, and obviously has a load of passengers jammed on the poop deck. I really think that they only dare send it out for a sail when the weather is almost a flat calm and even then only for a few hours. I don't know, but it probably has an engine inside it by now for safety reasons. To sail it properly, it would probably need to be loaded down a lot deeper than that. Still an interesting sight though, and I would love to have a trip on it if I was over there.
Bob