Does anyone have a hard answer to the requirements of when a passport is required when returning to US waters from mexico waters in a private vessel? This is all I've found w/regard to my question. Traveling to Canada, Mexico and Bermuda by Land/Sea Beginning January 31, 2008, the Department plans to move towards WHTI implementation at land and sea ports of entry by ending the routine practice of accepting oral declarations of citizenship alone. Citizens of the United States, Canda, Bermuda and Mexico will need to present the following to enter or depart the United States by land or sea: U.S. and Canadian Citizens Ages 19 and older: a government-issued photo ID, such as a driverâs license, along with proof of citizenship, such as a birth certificate or naturalization certificate Children ages 18 and younger: proof of citizenship, such as a birth certificate. Passports and trusted traveler program cards - NEXUS, SENTRI and FAST - will continue to be accepted for cross-border travel. Citizens from Bermuda Passport issued by the Government of Bermuda or the United Kingdom. Citizens from Mexico As under current entry requirements, Mexican nationals, regardless of age, must present a passport issued by the Government of Mexico and a visa, or a valid Form DSP-150, B-1/B-2 laser visa (Border Crossing Card). Trusted traveler program cards - NEXUS, SENTRI and FAST - will continue to be accepted for cross-border travel.