Final answer:
Commercial transoceanic travel requires authorization from appropriate governments and international treaties, which may include federal licensing for interstate travel in the U.S., international treaties consented to by the Senate, and special permissions under specific circumstances such as health-related restrictions.
Step-by-step explanation:
Commercial transoceanic travel must be specifically authorized by relevant national and international regulations and agreements. This process can involve a number of different legal and regulatory authorizations depending on the specifics of the voyage and the jurisdictions involved. For example, the U.S. Supreme Court case of Gibbons v. Ogden in 1824 established that the federal government has the authority to regulate interstate commerce, including navigation. Hence, for travel within the United States, the federal government would need to authorize/appropriate for passage through licensing or other regulatory mechanisms.
When considering international travel, treaties between countries can outline the conditions and understandings under which such travel is allowed. For example, during wartime, sovereign nations may issue warnings, as evidenced by the historical notice reminding travellers of the risks of sailing in a war zone. Transoceanic travel could also be subject to restrictions based on health concerns, as seen with individuals setting off radiation detectors and potentially needing special permission to fly.
In summary, multiple layers of authorization may be required for commercial transoceanic travel, including but not limited to federal licensing in the case of the U.S., international treaties to which the Senate consents, and any special circumstances that may necessitate additional government approval.