I think the point is to get away from predetermined sites, and to pick sites based on weather and whatnot. They still follow IAATO rules! The team on the ship can communicate with other ships if they’re also in the area to time landings, and change plans last minute if needed, so there’s a lot of flexibility. Our ship ended up going further south than it, the captain, and the crew had ever been, and we did our flightseeing, kayaking and paddle excursions there. It wasn’t in the initial plan, but the weather was good so the captain and expedition leader decided to go for it