When travelling between Canada and the United States by water, you must present one of the following valid documents as part of the U.S. Western Hemisphere Travel Initiative (WHTI) requirements.
All U.S. & Canadian citizens aged 15 and under only need proof of their citizenship with an original or photocopy of a birth certificate or citizenship card.
Groups of U.S. and Canadian citizen children ages 18 and under, when traveling with a school or religious group, social organization, or sports team, will be able to enter under adult supervision with originals or copies of their birth certificates or other proof of citizenship.
Entry into the U.S.:
A Visa may be required. For entry into the U.S., citizens of 37 countries (most of the European Union and several Asian nations) which participate in the U.S. Visa Waiver program are eligible to visit without a visa on trips of 90 days or less — view more information here.
Entry into Canada:
A visa may be required to enter Canada for citizens of some countries — view more information on visa requirements here.