Full, and longer than most people expect. Roughly 7am to 9pm, with a wake-up call, two off-ship excursions, meals in between, and an evening recap. It's an expedition rather than a holiday, and that's worth knowing before you book rather than discovering on day three.
The shape of it:
6:30 to 7:30 Wake-up call and a come-and-go buffet breakfast. Guides are already ashore scouting the site.
Morning excursion, about 2.5 to 3 hours. On a ship of 100 to 200 you'll be split into two groups, one ashore and one on Zodiacs, swapping halfway.
Lunch, usually buffet, while the ship repositions.
Afternoon excursion at a new site, same rotation.
Recap, around 5 to 6:30. Short talks from the guides tied to what happened that day, whether that was orca or an egg hatching. Then the expedition leader briefs tomorrow's plan and what to wear.
Dinner, a la carte, then something optional in the evening. A lecture, a film, a workshop.
The plan changes constantly. Ice, weather and wildlife decide where you go, and the briefing you get at recap is a best intention rather than a schedule.