Very nice, even though that may not sound like a lot. To most, that is hard and most can't do that.. I can jog 1 mile... Then I start to get a side ache, thats in gym when you never know when the miles coming so half the time I'm dehydreated but I wouldn't get much faster time... So it takes only 30minutes for 3miles? if so that is crazy!
For USMC, it's a requirement of 21 minutes which I will get this next year. I have 8 minutes to take off my time for that goal. It will be hard but very much worth it.