The stretch of sea between the southern tip of South America and Antarctica is the Drake Passage, an often turbulent stretch of sea that marks the beginning and end of your journey south. Take in the midnight sunset and watch albatrosses fly alongside you.
For two days on your journey south to Antarctica, and on your way back to Ushuaia, you will travel across the Drake Passage. This vast stretch of sea is where the cold polar waters converge with the warmer equatorial ones, pushing plankton and nutrients to the surface and providing a feeding ground for sea birds and whales. The Drake Passage is notorious for its rough seas, although at times can be as flat as a millpond. For many travelers, whether they suffer from sea sickness or not, this is very much part of the journey, and the reward on reaching Antarctica makes it more than worthwhile. Most journeys will be a mix of rough and smooth, and time spent on deck with a camera watching the sea birds congregate, and perhaps catching your first glimpse of a black-browed albatross in flight is a superb taste for what's to come.