Should You Say Godspeed?

Godspeed is an archaic way of saying goodbye, and is used in modern English in situations where very great earnestness is not inappropriate, such as a very dangerous mission, for example, where lives are at risk. It means “May God speed you”, that is, may God give you success.

Can I just say Godspeed?

Yes. If you wish someone God's speed or Godspeed, you don't need to say "wish" or "bid" or anything. You can just say "Godspeed." or "Godspeed!" like in both of those examples.

When should you use Godspeed?

The term Godspeed is sometimes used in order to wish someone success and safety, especially if they are about to go on a long and dangerous journey. I know you will join me in wishing them Godspeed.