You don't have to be super-fit, but you should be agile enough to climb down a gangplank into a bobbing Zodiac. She had no troubles on shore excursions, since some catered to light activities as well as energetic hikes and climbs. Marine Expeditions naturalist and passenger examine wildflowers on tundra. With Nunavut's Arctic exposure, it's possible to encounter natural risks. John Stewart told us about the time the ship became stuck in pack ice, requiring rescue by icebreaker.
Safety is number one priority.
There's a doctor onboard for emergencies. And there are mandatory lifeboat drills to orient passengers to the fully-enclosed lifeboats, which are equipped with water, food, medical supplies and signal beacons. Before each shore excursion, we were given detailed briefings about the weather, terrain and wildlife. Polar bears are taken very seriously. Gun-toting scouts ensure the areas are free of bears before passengers begin exploring.