After a very long stretch of short and/or very spartan vacations (if any) I've booked an Alaskan cruise for the end of August. This will be my first cruise of any kind. Departing from Vancouver, ports of call will be Juneau, Skagway, Haines, and Ketchikan. There are quite a few excursions to choose from, involving anything from bus trips to kayaking. I should be up to any physical demands that might arise during activities offered to the general public. I'm thinking at least one helicopter trip and bike tour (rented bikes-blech!) will be on my agenda. I probably won't be able to resist a brief foray into panning for gold. The fishing trip looks expensive, but I might try that, as well. I'll also have about half a day where I'll be fresh enough to see a tiny bit of Seattle. Though my cruise departs from and arrives back at Vancouver, I don't think my schedule or my baggage will favor my exploring that fine city. Tell me, what are some must see/do things to look for on such a trip? What might not be worth bothering with (and why)? Any reasonable chance of seeing an aurora around that time and those places?