A mile down and 40 miles out to sea off the coast of Louisiana, a BP-led team has been achieving unprecedented feats of engineering.
Bolting a new sealing cap to the top of the company's blown-out Macondo well in the Gulf of Mexico this week was the latest in a succession of efforts that have pushed back the frontiers of what is possible on the seabed in deep water. BP's attempts to staunch the leak have tested the expertise of its engineers to the limit. The operation has been compared to brain surgery, in the dark, from 5,000ft.
For staff steeped in a culture that prizes technical capability, the skill and creativity of the Houston-based team working on the spill have been a source of pride.