The Q4000 DP3 semisubmersible vessel entered service in the Gulf of Mexico in 2002 and has since built one of the most extensive well intervention track records of any vessel in the world. Its stable design and unique open deck make the Q4000 an optimal platform for a wide variety of tasks, including subsea well intervention, field and well decommissioning, installation and recovery of subsea equipment, well testing, and emergency well containment. Among the Q4000’s notable features are its 600-metric-ton multipurpose tower capable of fulfilling all traditional derrick roles, a deepwater crane with lifting capacities to 360 metric tons, and a work crane rated to 160 metric tons. The open deck plan enables quick and efficient loading and offloading of project supplies and equipment in a single lift.