What's required to confirm:

Domestic Trips

Scheduled Trips
A $200 refundable deposit per person is required to reserve space. Full payment is due 30 days prior to the trip start date.

Custom Date Trips
A $400 refundable deposit for the entire group or individual, or 20% of the total balance for a group (Whichever is higher).

International Trips (and Alaska)

Scheduled Trips
A $500 refundable deposit per person is required to reserve space (or half of trip cost, whichever is lower) Full payment is required 90 days prior to the trip start date.

Custom trips
20% of the trip cost. Full payment is required 120 days prior.
Keep in mind that reserving a spot with a deposit is with no obligation outside of the cancellation period! (See below)