[TheGeoff]

Good questions!

• Does using the radar make me easier to detect by enemies?
  Not at the moment. In the future, however, some enemy vessels and aircraft will be able to detect and track your submarine's radar emissions.
  
  
• In the weapons system, if ships are "unknown vessel", how do I identify them?
  To determine the exact type and name of the ship you need to get close to it (within ~6 nautical miles) while at periscope depth or shallower. The ship's name, nationality and type can then be seen by viewing it through the periscope (T to cycle targets).
  
  
• What else can I do with the sonar, besides scrolling through ship signatures with + and -?
  You can also target ships by pressing 'T' to cycle through sonar contacts. If you select a target this way before firing a torpedo, the torpedo will automatically track the target vessel. Targeting a sonar contact will also show its sound signature on the LOFAR analysis screen, allowing you to identify the ship by comparing its signature to the database.
  
  
• How do I read sonar signatures? I don't see how the signature lines and sonar output correlate.
  Select the sonar contact by pressing T until it is highlighted. The contact's sound signature will now appear in the LOFAR analysis screen - you can determine what type of ship it is by comparing the signature to the database.
  
  
• If a steam turbine is damaged, does it suffer further damage if I keep it turned on? The turbines always seem to fail spectacularly.
  Most mechanical systems on the submarine (turbines, generators etc) have a speed governor which prevents the machine from exceeding safe limits on speed, power output etc. If the governor is damaged, other components in the system (like the rotor) may also be damaged if the system is not promptly shut down. If a turbine is damaged you should immediately shut it down using the turbine control panel so it can safely be repaired.