Yes, it was through NCL. We went last October and loved it. It was our first trip to Hawaii and we took our kids with us. We used the ship as our floating hotel and was able to experience the different islands. Once you decide on your date, go to cruisecompete. Then several agencies will bid on a price. I remember doing this a couple of times. I think the bids do expire and perhaps, that is why. . . Can't remember for sure now. I spoke to several agencies and the one that we went with was Cruise Vacation Outlet. There were a couple of others that had close prices and seemed fine, too. Don't remember their names. I was a bit hesitant booking myself, but I checked the agency with BBB and through forum boards. It worked out fine for us and we saved money. I know there was a thread on cruise critic I believe about what to ask for to be sure that you don't get scammed. Read through those boards. Be sure your deposit goes directly through to the cruiseline. I remember calling the ship and verifying.
I saw another post on All Seas Travel. We have booked through them, too. They are very nice and very informative. Not sure if the price was any better than going directly with cruiseline, however.
Good luck!