This is a guide how to make the Naval Supremacy mod work with ntw3.
It's best features i have to say are graphical like reskinned new historical ships and marines, here you go:
Download NS 1.1.3
http://www.twcenter.net/forums/showthread.php?t=360966
Replace "unit_pack_compatibility_project_napoleon_v2_4_DEKNS.pack" from Program files\Steam\steamapps\common\napoleon total war\data with this one (I took the liberty to rename some Portugues ship types):
http://www.mediafire.com/file/gv6vn3...2_4_DEKNS.pack
Your user.script in C:\Documents and Settings\User\Application Data\The Creative Assembly\Napoleon\scripts (Windows XP) should look like this:
Note!! you should play after started first a NTW3 campaign, from the vanilla shortcut, if you play from the NTW3 Manager it will overwrite your user.script
It should be save game compatible.
credits go to Iutland for his amazing mod.