Oceanography may no longer be only an Earth science. Evidence continues to mount that Saturn's giant moon, Titan, may have seas of liquid hydrocarbons that exhibit many phenomena familiar to terrestrial oceanographers, but with an other-worldly flavor (Figure l ). In less than two years, the Cassini-Huygens mission, a massive joint undertaking of NASA, the European Space Agency, and the Italian Space Agency will arrive at Saturn and begin exploring the strange world of Titan. Our goal here is to introduce Titan to the oceanographic community, to outline the data to come, and prompt new modeling efforts. We pay particular attention to phenomena observable from Cassini, although we note that many terrestrial phenomena—only now beginning to be surveyed on Earth via moored instrument networks, submersibles, remotely operated vehicles (ROVs), and autonomous underwater vehicles (AUVs), etc.—may have analogues on Titan. We anticipate that Earth will have much to tell us about oceans on Titan, and vice-versa.