You may pay when you arrive, but discounts are only available online. When you make a reservation with us, we ask for your credit card number and information. We use this information to reserve your seats on the tour. When you arrive for the tour your credit card will be charge. Again, if you do not pay in advance you run he risk of missing out on the online discounts. Additionally, we reserve the right to charge for the activity if you do not cancel within cancelation policy limits (see above). You are responsible to call us in the event of a cancellation or rescheduling (at least 48 hours prior to your activity time).