Thanks, for the info, Beth. Unfortunately, the vistors center is under major renovation so we don't know whether it will be fixed or not.
It is just very difficult for us to do any of the included tours anymore with any kind of walking. We can't keep up with the group so don't hear the guide and are often way behind getting back to the bus.
So I think we will still do a private excursion.
We don't mind the tours that don't have a lot of walking.
This is one reason we are trying Seaborne in 2013 so we don't pay for excursions we can't do.