I hesitate to say anything but I will. Please take my comment from what I expereienced last year. I went at almost the same time as y'all are going this year I think there was a day difference in departure.
We booked the Tracy Arm excursion through Radisson. When we boarded the ship, there was a note in the cabin that it was cancelled and they gave some other tour in place (one that was listed that we had no interest in).
The point is that the reason it was cancelled was that they said they could no longer do it because of the time of year or something like that. I honestly don't remember the whole reason but it was totally cancelled. they gave us a refund for the tour that they choose for us but we didnt' want. So if you have any way to know in advance because y'all are a group maybe you can find out in advance if it's still going otherwise you might be giving up another choice that y'all want to do but don't because of you wanting to go on this one.
I don't know if this was just a one time thing and other times it does go at that time of year or that something went wrong or whatever but I didn't know till I got on the ship and looked through what was left for me in envelopes. Maybe they said it had something to do with the daylight hour. I can't remember and I'm sorry, I wish I could.
I hope what I'm writing makes sense. Anyway I saw this thread and just thought I would mention this. There were a lot of disappointed people on the cruise, The captain did a wonderful job of going through Tracy Arm and Terry Breen did a wonderful narration and we saw the twin Sawyers but not as close obviously.
Please don't base your choice on what I write because maybe it was just a one time thing, or something just went wrong that one time, but I thought I would write and mention it in case it is of importantce.