Most Princess naturalists are very experienced and have been in Glacier Bay dozens of times. They will know the timings and when to be on deck. However you should find your naturalist and talk to them before Glacier Bay. The rangers run the show while in the park and the naturalist gets the day off so to speak. A few of the places are the park entrance and Icy Strait (whales and sea otters), South Marble Island (sea lion haulout), Gloomy Knob (mountain goats), and from Russell Island up to the glacier (bears on the beach). If you don’t have binoculars, don’t bother, as you will only see dots.