Re: Liveaboard Commuting to D.C.
As mentioned by several, the best option depends greatly on where you will be commuting to, how often and when.
I lived on Back Creek in Annapolis and comutted to Pentagon daily. I planned 90 min each way, but 60min of it was relaxing/reading on metro train.
Another option I considered was Fort Washington, MD. Its just across the bridge from Alexandria, VA. (which was under construction at the time, so I declined) Reasonable rates and choice of two marinas.
Good luck. Let us know what you decide.