Transocean sued Maersk for patent infringement over multi-activity offshore drilling rigs. Maersk had signed a contract in Norway to sell a rig to a US company for use in the Gulf of Mexico. The Federal Circuit found this constituted an "offer to sell" and "sale" under US law, even though negotiations and contracting occurred overseas. The court also ruled secondary considerations showed the patents were not obvious and claims were sufficiently enabled. Maersk was found to infringe but not willfully so.