I like the general idea and the perspective seems to have solid foundation but i still don't really understand the size relations man-tree-buildings in the back... Putting the man on one head and the tree on the other should make it clear but i think the "road" ruins it because it doesn't follow the perspective grid-i believe it should be much wider closer to the viewer and a lot thinner round buildings.
Adding more underwater is something i like and would encourage you to continue but add more details, something interesting to see down there.
The submerged statues look really cool, and so do the buildings and the ships in the air! The whole sceene is interesting, do explore it further!