Helix Energy Solutions is in the energy services mix as a top marine deepwater contractor. Its Contracting Deepwater unit primarily works in water depths ranging from 200 to 10,000 feet, using dynamically positioned and remotely operated vehicles (ROVs) that offer a range of engineering, repair, maintenance, and pipe and cable burial services in global offshore markets. Former subsidiary Energy Resource Technology (ERT) bought and operated mature fields, primarily in the Gulf of Mexico, but in 2013 Helix Energy Solutions sold this business in order to focus on its offshore contracting operations.