FSX FS9 add on in FSX

I am totally new in creating scenery.
While learning, I need some help here.
I uploaded several FS9 scenery/airfields in my FSX addon. Most works well but there are some that do not.

One of the airfield is on an island. In FS9 the airfield is located on an island but in FSX the surroundings are covered by sea water, only a part of the island can be seen. 80% of the airfield is above sea water but most of the island and nearby islands are covered by sea water.

Is there a way to correct this. How do I do that?




Hm, pretty complex stuff and many things that must be considered here.

And many things i dont know. Just on thing. As far as i know not all landclass from FS9 work in FSX, and thats probably whats wrong here. Cause it could be that in default FSX you dont have land where the island is.

So first step would be to rebuild the landclass for FSX