I'm very happy with our results for the second quarter 2012 and some of the significant accomplishments that we posted in recent days. Second quarter results included a 14% improvement in revenues along with higher margins, both driven by a continuation of great market fundamentals. Also, our revenue efficiency improved with our unpaid downtime declining to under 3%, as we continue to experience some benefits from a number of operational and process improvements put in place over 2011 by Bernie Wolford and his team. There remains plenty to be done, but we are encouraged by the early results. James will address these quarterly highlights in more detail in just a minute.
Another area I'm delighted with is the steady improvement in numerous milestones we continue to record on the fleet transformation front. Recall at one point, this rejuvenation program involved 14 separate newbuilds with a number projects now down to only 11 following deliveries of the Noble Bully I, the Noble Bully II and the Globetrotter I last year. Although this remains a formidable task, our execution is beginning to reach the levels that we have always expected due to the strong efforts of Scott Marks and his team, our project managers and engineering group.
Let me give you a sense of the newbuild milestones that we have either met or expect to meet during the month of July. We launched the hull of our first HHI ultra-deepwater drillship, the Noble Don Taylor. The rig should complete construction activities in the second quarter of 2013 and following mobilization and commissioning, be ready to commence this drilling program in the second half of 2013.