MV Plancius, formerly HNLMS Tydeman (A906), is a renovated oceanographic research vessel of the Royal Netherlands Navy now employed as a polar expedition cruise vessel by owner and operator Oceanwide Expeditions. She was commissioned into the Royal Netherlands Navy on 10 November 1976, and served until 2004, before being renovated for commercial use. The vessel was used for both military and civilian research and had a fracture zone named after it.