Here's a link to my mod of Toma Gabriel's Skipjack SSN mod. It's only a small file but it modifies the campaign and flotilla files to enable the player to start at Pearl Harbor. It makes more sense to play from Pearl as the waters that the Pearl subs operated in tended to be nice and deep compared with the subs down in the South West of the Pacific theatre.
Link:
http://www.filefront.com/user/forensicman