Viator is a booking company not a tour company. Viator contracts out the tour to local tour operators.
If there is a problem with the tour operator or schedule or pick ups they simply tell you resolve the issue with viator because you booked thru a 3rd party and they simply absolve themselves of all responsibilities. If you attempt to call Viator they can't remedy the problem before the tour departs they are totally inept. I would proceed with caution booking thru Viator and certainly not recommend them. All of this stems from a tokyo trip whereby they directed me to the wrong location and wrong tour operator and could not resolve the issue.
In all fairness i have used them in other countries and they were at the mercy of the local tour operator. My suggestion is book directly with the local tour operator.
Reason of review: Poor customer service.