Check this out, courtesy of Ubisoft: http://support.uk.ubi.com/online-services-platform/

Long story short - you need a permanent internet connection in order to play a single player game. No, not like Steam, where you have an Offline mode. If you lose the connection to the internet, your game pauses, and if it can't reconnect you have to wait to reestablish connection and load up your last save game.

Meaning if you haven't saved for, say an hour, you lose that hour, just as if your computer crashed.

And all this for the following features!

Unlimited installs (wow, I am stupefied, UNLIMITED installs, rejoice people, rejoice!)
No need for the game disc to play (you know, I am now sorely tempted to seek out the services of other "providers" which also offer the same benefit)
Online storage of save games (ok, this is just too funny)

Guess Silent Hunter 5 is a game I certainly won't be buying. I wonder which lobotomized "anti-piracy" manager managed to come up with this one... all I can say is