Are you Canadian and are you flying to the US first.
Canadian citizens travelling by air to, through or from the United States must present one of the following valid documents:
a passport; or
a NEXUS card when used at a kiosk at designated Canadian airports and at all U.S. airports when returning to Canada.
This requirement applies to all travellers, regardless of age, including children.
U.S. entry requirements have not changed for Canadian citizens who are U.S. lawful permanent residents (LPRs). U.S. LPRs may continue to present their permanent resident card (Form I-551) or other valid evidence of permanent residence status in the United States.
Note: Under U.S. law, all travellers (including Canadians) departing the United States by air to any destination (including Canada) must present a valid passport (or a NEXUS card for return to Canada only). For example, if a Canadian citizen enters the United States by land by presenting acceptable documents other than a passport, and then plans to board a flight in the United States destined for Mexico (i.e. an international destination other than Canada), a valid passport is required for the air travel portion. Similarly, if a Canadian citizen drives to the United States and returns to Canada by air, a valid passport or a NEXUS card must be presented to board the plane. It is important to note that a passport is not mandatory for air travel within the United States.
Canadian citizens intending to fly to, through or from the United States should apply for a passport, keep it up to date and carry it with them when travelling. For more information about passports, please visit Passport Canada's Web site.
The NEXUS program offers a simplified and expedited border clearance process to low-risk, pre-approved travellers. For more information, visit the NEXUS Web site.
U.S. entry requirements have not changed for non-Canadian citizens, including permanent residents residing in Canada. For more information on U.S. entry requirements, consult the U.S. Department of Homeland Security's Web site.
For information on the new Passenger Protect program for air travel within Canada, please visit Transport Canada's Web site.
Date Modified: 2009-06-19
If you are driving to the US I am not sure if you need a passport for the kids under 16 to cross adults do for sure.
For the cruise it is a closed loop cruise so you would not need a passport but if you need to fly back to Canada/States you would need it.