What does speedy mean?

Barring injuries or illness, I know I can complete 26.2 miles in one day. The question is, how fast?

I have a couple of speed aims for my marathon:

• At a minimum, not to get kicked off the course - there is a 6 hour time limit, after which a bus scoops up stragglers to bring them to the finish (disastrous outcome IMHO).
  
  
• Ideally, to run the whole thing, at a pace that will not cause marital discord. We haven't talked in detail about this, but at the moment I think hubby and I would like to run together. In order for him to tolerate that, I don't think I can go slower than 10 and a half minutes per mile.
  
  
• In my wildest dreams, I'd be thrilled to achieve a pace that allows hubby to better his San Francisco time of 4 hours 18 minutes. That's under 10 minutes a mile and is definitely a stretch target.

Photo thanks: Gil Ros.