More on Diamond Offshore's (DO) Q4 results: Lower day rates offset improved utilization of ultra-deepwater and midwater floaters. Ultra-deepwater day rates fell 2.2% while utilization rose to 89% from 70% Y/Y. For deep-water floaters, day rates dropped 12% while utilization fell to 85% from 97%. Day rates for midwater floaters fell 1.1%, with utilization rising to 70% from 60%. DO +0.5% premarket.