Balasar mentioned the weird behavior of the levels, wich is quite different from the other maps. I am not very happy with this, too.
Unfortunatly the map was build without giving enough thought into this at first, thus the dimensions in the map are somewhat unfavorable. Changing this (= cutting the map to make it fit the level heights) would result in a lot of "dark", e.g. in first level and second level only the water and small parts of the ships would be visible. I took a shot at this in the beginning, but it did not make things better.
This is something I will do as soon as I have a nice idea how to do it. There are some other things left. Most important, the ships are not really a part of the map, as only very small parts can be used for now.