There is no dedicated parking for this activity and you can expect to have to park 1/2 mile to 1 mile away if there is even any place to park at all. Don’t drive a truck and expect you can park in Bar Harbor.
Viator also provides NO communication to make participants aware of the parking challenge. We missed the tour and were denied a refund despite arriving 30 minutes prior to departure. Arrive 1-2 hour ahead of time and pray you can find parking.