I think he meant "beyond" instead of "above" when referring to the depths stated of 50m and 30m.
As for how you would modify these behaviors, Antar, I can only recommend you begin with the proper tools.
For editing and comparing the config files ( .cfg ), I highly recommend Notepad++ as it is well made for editing many types of text files.
Silent 3ditor ( S3D ), by skwas, is the absolute best tool for editing many features in Silent Hunter 3 and Silent Hunter 4.
For modifying graphics and textures, Photoshop is ideal. Two free alternatives are Paint.NET and GIMP.
Irfanview is excellent as a multimedia viewer that supports virtually every format there is and its batch conversion feature is very useful when you need to convert one or many graphics to a different type.
For modfying the 3D models, you'll need something like 3DS Max or Maya. Two very good free alternatives are Blender and Wings 3D.
Aside from this, there is not much else I can tell you except to explore the game files yourself and figure things out. I do know that most of what you wish to find can be found in the files for the uboats.
Look inside your Silent Hunter III installation folder. Inside you will see a folder called 'data'. Nearly all data and information the game uses is in this folder.
Inside 'data' you'll see another folder called 'Submarine'. This contains all the uboats that the game uses. inside of 'Submarine' are several folders, each named for the type of uboat. For example, the folder for the type VIIB uboat is labelled 'NSS_Uboat_7b'.
Inside each of those folders you'll find files with the extensions of '.cfg', '.dat', '.sim', '.val', .'cam', '.dsd', '.zon'., and '.eqp'.
What I do know is that the configuration (.cfg) files contain many settings that control how the uboat works. The equipment (.eqp) files contain settings for what types of equipment and weapons a uboat can carry. Both of these are text files that can be viewed and edited with any plain text editor.
Simulation (.sim), Value (.val), Data (.dat), Zone (.zon), Camera (.cam), and Direct Sound Data (.dsd) files can all be opened and edited using S3D.
Zone files control how a uboat takes damage by establishing 'hit point' zones for each area of the uboat hull.
Data files contain the actual 3D models and textures of the uboat.
Simulation and Value files deal with many effects and behaviors, such as the bow splashes and the turning radius of the uboat.
Camera files are just that, the camera or "eye" with which the player views the envrionment. Things this controls, for example, are the position you're standing in when you switch from one station in the uboat to another.
Direct Sound Data files control the various sounds that are associated with the uboat.
For the inside of the uboat you'll want to look into another folder inside 'data' that is labelled 'Interior'. There are folders for each uboat type inside that also contain files for the interior of the uboat.
These are just two places to look. You'll likely need to investigate files in the other game folders to find what you need but this will hopefully give you a start.
I wish I knew more to help you better. Good luck and looking forward to your mod being released!
