Hello. If you have a few bucks to spare, get it on Steam. I know that many skippers here are against that but if you really, really, really want to play it right now you might want to consider that.
If you do decide to get it on Steam, keep in mind that the stock game will be separate from the U-boat missions so you are going to have to purchase them both as the stock game on Steam isn't updated to 1.4
http://store.steampowered.com/app/15200/ - Silent Hunter 4
http://store.steampowered.com/app/15240/- - U-boat Missions Add-on