Hitch-End Decay Curves in Deepwater Drillship Crews

A deepwater drillship in the US Gulf generates a distinct crew-energy decay curve that looks different from a jackup's. The water depth adds complexity the crew absorbs across a 28-day hitch. This post compares the decay curves, drawn from four drillship rotations observed over 16 weeks.

Four deepwater drillships in the US Gulf — three operating in 5,000-8,000 feet of water, one in 9,200 feet — were observed across 16 weeks of 2025, covering four full 28-day rotations. The 2025 IISE four-week GOM drillship fatigue assessments study independently documented declining PVT performance and sleep efficiency by week four of rotation in the same region. The decay pattern the garden rendered matched the published curve on shape but added rig-level detail that averaged studies necessarily smooth over.