Reservations online or by phone are recommended but not mandatory for two of our three tubing trips. Shenandoah Mellow Harpers Ferry Tubing does allow for walk-in tubers as does Whitewater Tubing Harpers Ferry. However, the walk in rate is higher per person, and it does take more time at check-in. In addition, if you are tubing during a less busy time of the season, walk-ins may not have a driver readily available to shuttle them. For the two trips listed above, an online booking discount is available up to one hour before the trip time during our busy summer season. Potomac Mellow Tubing does require a reservation, however, spots are sometimes available on the morning of the trip.