Did a "pilot's choice" excursion out of Juneau late June 2001. The weather was beautiful when we took off and the glaciers were magnificent! There were two landings. Between the first landing and the second, it began to get a little cloudy. On the second glacier landing the pilot encouraged us to walk around and told us we had 20 minutes or so to get back to the helicopter. Suddenly, fog developed and all the chopper pilots (there were serveral about, but none close enough to each other to be bothersome) were frantic to get the passengers back to the helicopters in time to take off before the fog worsened. On the way back to the hanger, our pilot told us that occassionally groups get socked in for several hours at a time due to fog (once overnight). Though we didn't get "grounded", I'm glad we booked that excursion with Princess just in case. It was an amazing experience! I would do it again without hesitation!