The easiest way to do "modding" things is to copy someone else's mod, and add your own flavor to it. If you happen to want to share your creation, you ask permission from the original modder to use their work.
Now, this is a rather old post, so a lot of the links won't work, but it gives you an idea of what has gone before you, prior to October of 2009:
Playable Surface Ships Mods List
For the Iowa Class itself, there is a BB-63 USS Missouri here at SubSim:
http://www.subsim.com/radioroom/down...o=file&id=5165
Bismarck notes that he gets crashes (at that time) in his mod. It's not easy getting something to truly be "playable" in SH4 - even submarines (
)...
For all of the playable ships here, look in the Downloads section:
http://www.subsim.com/radioroom/down...p?do=cat&id=77
None of the mods are going to be "perfect", but you'll find that some ships are rather "smooth" and work nearly flawlessly compared to others. Those are the ones to copy. Someone more familiar with the surface ships would have to comment on which are better. You can use WinMerge or similar to compare files in the mods to files in stock SH4 to see where the differences are.
You can use surface ships in the campaign, so long as you're careful where you have the ship start, and what the assignment is. It's easiest to get them going in a Single (Quick) Mission or Patrol, but be sure the depth setting for the mission is zero, on the surface. It'd be embarrassing to start a missions already sunk
... it'd probably cause a game crash anyway.
