Please answer the following question: Deepwater Nautilus -  Deepwater Nautilus is an ultra-deepwater semi-submersible offshore drilling rig. Built in 2000 in South Korea she is owned by Transocean registered in Panama and leased to Royal Dutch Shell for drilling operations in the Gulf of Mexico until December 2011. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
Answer:
Mean Of Transportation