When looking at accessible tours look for
in the excursion list
Most have a note at the bottom of the description
"PLEASE NOTE: Tour includes step-free routes, shorter distances and no stairs. Accessible restrooms with wide doors for wheelchairs are present along the tour route. Vehicles are adapted with an access ramp (or lift where available) to accommodate a limited number of wheelchairs and/or mobility scooters. Guides are not allowed to push wheelchairs; therefore, guests needing special assistance must be accompanied by an able-bodied."
If you do not have a mobility issue do not book the tour & leave them for those that do
They may not have accessible tours at each port