Yeah - if you just save your game and reload it, that usually fixes it - I've had a similar thing happen with silent running - I try to turn it on but despite the command being acknowledged the icon refuses to appear - this is usually followed by depth charges dropping like confetti. Something I have noticed though, is that the game stores periscope photos - the ones you take on photo recon missions - they're in the Documents\SH4\Data\Photo\ folder. The quality isn't great though - This is one....
